"Hey pal, what are you gonna do? Save the world all by yourself?"
KOEI's Dynasty Warriors/Samurai Warriors games have the entire game based around butchering your average soldiers as well as enemy officers. This doesn't seem to be much of an achievement, however, as it seems a majority of soldiers in Ancient China were trained to stand there and stare dumbly at their opponents Justified, since certain characters (Zhang Fei, Lu Bu, among others) are so legendary that entire armies will balk or flee at the sight of them.
Zhang Fei's claim to fame was defending a bridge by himself against Cao Cao and a thousand or more of his troops. Cao Cao was worried of an ambush on the other side, but still.
Zhuge Liang one-ups him in the novel by defeating Sima Yi literally by himself, armed only with a fan and a teapot and accompanied by only an unarmed servant boy. Basically, Sima Yi of Wei is approaching with a huge and formidable army. Zhuge knows his own forces are tired and cannot beat this force, so he orders them all to retreat. He then sets up in a city which he has earlier cleared of people, sitting above the wide-open city gate calmly drinking tea and fanning himself. The Wei army soon arrives, and Sima Yi can scarcely believe his eyes—an unarmed Zhuge Liang right there for his taking?! Having previously suffered multiple times from Zhuge's perfidy, Sima thinks it's just another trap and orders a general retreat.
Considering that the way they trained the lower level soldiers at the time was to pick a random farmer, put a spear into his hand, and say, "Have fun". The trained officers exploits may not have been exaggerated much either.
Sengoku Basara is a worse offender. In Koei's series, at least your allies do something good when they're not in front of you. (Some of the time, anyway. Other times...) In here, they practically do nothing but stand there like an idiot, and you REALLY have to be a One-Man Army to survive. But with flashy moves given, well I don't think it's a problem.
If there's any person who should be fit to provide the picture for this trope, it would be Captain Titus of Warhammer 40,000: Space Marine. Why? Well, not wanting to spoil too much, but he makes other One Man Armies look comparatively sissy compared to what he's dished out over the course of the game. Deconstructed at the end. The sheer ridiculousness of Titus' deeds make the Inquisition suspicious of him.
In The Battle for Middle-Earth, it's possible to rack up thousands of vanquished enemies with Gandalfin a single battle using his Word of Power attack. Having tens of thousands of kills at the end of a campaign is not unheard of.
Your custom heroes from the sequel can be this trope, too, given that you've selected the right powers. Some players put all their skill points into armour, which makes the hero capable of surviving three times the damage a normal hero unit can take, and then give him powers that allow him to curbstomp a whole squad of enemy heroes or monsters.
Non-campaign maps will have a stealthed Gollum running around. Killing Gollum gets you the One Ring, and if you take that to your fortress you can recruit a Ring Hero. For Men, Elves and Dwarves it's a powered-up Galadriel... but if you're playing an Evil faction (Mordor, Isengard, Goblins or Angmar) you get Sauron, who can pretty much wipe out an entire army and an enemy base by himself.
This Troper knows for a fact that using a custom elven hero means gaining an immortal unit, used correctly it is quite literally possible for an elven hero to be healed indefinatly meaning that they can hold off an indefinite amount of units at once, it requires constant attention once the hero is fighting thousands of troops at once, but still......
Thats notthing, using a specific glitch in the hero creation system,, its possible to make a hero that can (among other things) be immortal as above, summon tornadoes, cause earthquakes, jump hard enough to kill armies, and punch shockwaves. And many of those can be used on one character, this Troper created one character that could fight even the ring heroes on even terms (well considering the immortality factor, maybe not so even....).
In Sengoku Rance, it's possible to make any foot soldier unit in the game into this by giving it the Fellow Troops' Revenge ability, which allows a special attack that deals damage equal to the number of casualties the unit has suffered. Since troop counts can easily reach and exceed 1000-2000 men per unit in this game, a foot soldier unit that's been reduced to a handful of men (or just one, ideally) can slaughter hundreds of troops per turn, assuming you can cover them with other infantry units and keep an enemy counterattack from wiping them off the map.
Of course, the most literal example would have to be Ogawa Kentarou after becoming a demon.
Fire Warrior (of Warhammer 40,000 fame) played this trope to terrifying limits. Not only does La'Kais kill several battalions of the Imperial Guard, large numbers of Space Marines and several Dreadnaughts, a good deal of Chaos Marines and several Daemons including a God by himself - he does it all within the timespan of twenty four hours. This is even more amazing when one considers that La'Kais is a Tau Fire Warrior, making him the Tau equivalent of basic infantry, a common foot soldier. Furthermore, not just any day—La'Kais' first day of live combat action. (Hmmm...) It's worth noting that canonically, he was driven insane by his experiences and was never fit for duty again.
At least, up until around the Eye of Terror world campaign, at which point they brought him back (for the Tabletop Game) as O'Kais (Shas'o being the equivalent of "general", while shas'la is roughly "private". Yeah, Tau nomenclature includes lots of compounds, and an individual's rank and caste), and used him as the justification for introducing man-portable railguns as a sniper-rifle analogue. They still note that he was a basket case, but he gets roped back in for a completely undefined 'emergency'.
The Novel offers a few justifications: one, (Khorne was helping); also most of his kills were from blowing up a ship's engine (flushing hundreds out into space). He's still pretty messed up.
In the World War 2 game Blazing Angels, you play as a pilot known as 'Captain'. You manage to accomplish by the end of the game the feats of destroying half of the Blitz bomber force, stopping the Blitzkreig at Dunkirk, destroying the entire Midway invasion force, destroying virtually the entire Pearl Harbor attack force, raiding the Japanese base of Rebaul and devastating the airfield there, taking out the top secret Nazi nuclear project, destroying the entire D-Day bunker network,, stopping Operation Bodenplatte, destroying the Berlin radar network, surviving a three minute dogfight with the rest of Germany's airforce by yourself, and taking out an elite jet squadron. And the said jet squadron insults you by saying they have jets and you don't.
Indeed, the PC Call of Duty games were intentionally intended to avert this by using a more team-based single-player game, and having a campaign that shows the war from multiple perspectives—given the improbably large body count the player still racks up at times, they were only partially successful.
The attempt in the first Call of Duty is largely useless, as allied NPCs and enemies will stand point-blank discharging their weapons at each other. Eventually the player will lose all of his allies unless he takes over the killing.
In Call of Duty 4, it will vary within the mission; in the first, "Crew Expendable," you can literally let the AI do all the work for at least the first quarter, just following from the rear, until the first skirmish where there's a realistic chance for the enemy to hit you. Conveniently, you are spared poor orders-following AI by not having control over your team at all.
In Call of Duty: World at War's multiplayer, if a MarineRaiders player gets a high enough killstreak, their character sometimes yells, "I'm a One-Man Army!" in what seems to be this trope combined with lampshading.
And Modern Warfare 3 follows suit with the "Specialist" strike package, allowing a player to actually gain more perks as he makes kills - managing to get 8 within one life gives that player the advantages of nearly every perk and weapon proficiency in the game.
The challenge for earning the 8 kills in one life bonus is called OMA.
In most fighter (or starfighter) simulations, the player character pilot typically accumulates a kill score in the hundreds over the course of a career, or even a single campaign. It's common to make "ace" (traditionally five kills) during the very first mission. If the game includes a kill board, the protagonist soon outpaces the other NPC pilots, sometimes by an order of magnitude.
In Freespace, you're not considered an ace until you have 60 kills!
In Elite, in order to reach the ultimate Elite ranking, you have to kill over 6,000 ships.
This does take around 20 in-game years if you want to be able to make enough money to keep your ship repaired, armed, fuelled and with a working drive.
Ace Combat is the best example of this trope as allied pilots are nothing more than moving distractions but the player massacres an entire country's air force (and in some games, army and navy, too).
This isn't entirely true in Ace Combat 5: The Unsung War or Ace Combat Zero: The Belkan War, where your wingmen will occasionally shoot down enemy planes and destroy ground targets. That said, a grand majority of the property damage in the game is caused by the player. Note as a contrast that while the notoriety of Wardog Squadron in 5 is for the whole flight group, there's only one Demon Lord of the Round Table in Zero...
Ace Combat 6 has allied units who are actually useful; and under the right circumstances, can jack up any target with a Macross Missile Massacre. This can be very essential to certain achievement runs (such as guns-only Campaigns or those where you have to fly only one of the three plane types) and especially when it comes to taking down Strigons.
"Head Operations has recognized you asan indispensable component in this war."
Ace Combat 3: Electrosphere seems to play it straight, until the Omega Ending (only in the Japanese version) reveals that Nemo was an AI and the entire conflict was just a simulation to create a pilot that could beat Abyssal Dision. This was true in almost all cases, though the outcome of the war itself never really changes. Japanese fans of the series were not happy about this, which is likely why later games play it straight. Tropes Are Not Bad.
In TIE Fighter, it is in fact possible to destroy one of the big Rebel cruisers with a TIE Fighter. The warship has shields and many laser turrets; the fighter has no shields, no warheads, and only two laser cannons. Of course, it's nearly impossible to do this if other ships are around; even with just the one ship, it's a pretty big accomplishment that requires a lot of hard work and fancy flying. Similarly, in its predecessor X-Wing, the first 12-mission campaign centered around an elaborate plot to smuggle a bomb onto a specific Star Destroyer to blow it up; however, a sufficiently skilled pilot could shoot down that specific Star Destroyer (which acted as the base for the enemy in every mission) with a single X-Wing every single time, leading to promotion to general and every combat medal in the game bing awarded after the first mission.
In the final game of the series, X-Wing Alliance, it was laughably easy to become an instant ace in the very first official mission. In the training missions, LucasArts Totally Games even accounted for the very skilled players, by having recorded lines from your trainer if you manage to, for example, destroy the entire convoy.
In order to gain complete control of Los Santos, the protagonist of Grand Theft Auto: San Andreas must kill in total thousands of rival gang members armed with AK-47s and other heavy weaponry, usually 30-40 per "territory", and that's not even counting police forces, mob gangsters, hitmen, FBI agents and the US military. Furthermore, because gang members are instantly replaced (or healed by paramedics), it's possible for the player character to wipe out the same gang several times over in the course of minutes. Occasionally lampshaded:
Ken Rosenberg: Oh yeah, he's a real one man army! Real fuckin' dependable.
In fact, all of the various Grand Theft Auto protagonists singlehandedly accrue impressive kill counts.
In Half-Life, Gordon Freeman starts off as an unassuming theoretical physicist whose job basically amounts to manual labor. But one resonance cascade and crowbar pickup later, Gordon is a virtually unstoppable badass who fends off not only an entire invasion of incredibly lethal aliens, but also whole platoons of crack soldiers. When he returns in Half-Life 2 he finds that he has become a legendary figure whose mere presence is enough to precipitate a worldwide revolt. (No doubt his nigh-unique "hazard suit" helped, but it amounts to a bit of a handwave.)
This was also lampshaded in Half-Life 2 in Dr. Breen's message to the Combine forces:
Freeman's Mind mentions several times Freeman's increasing body count and the ramifications thereof. "Man, if I get indicted once I leave here this is getting harder and harder to explain. I don't think anyone's gonna buy a few dozen counts of self-defense with a submachine gun."
By Episode 31 he changed his mind again to a more Raoul Duke-like attitude: who would believe the prosecutor if told that he, Gordon Freeman, an untrained scientist, survived monsters, killed hundreds of marines and launched a missile?
You have to be a complete Badass for the enemy high command to name you Anticitizen One.
Gordon is so badass that he's hired by interdimensional aliens, ostensibly as a walking weapon of mass destruction.
The lack of psychological damage is justified as he's been training for this since he was six, with the UNSC taking particular care to make sure that he and the other Spartan-IIs would be able to remain mentally stable no matter what. Note that in the expanded universe, the Spartan-IIIs are created with less attention to their psychological well-being; Lucy-B091 remained Dumb Struck for 7+ years after a mission which killed all but two people of her 300-strong company.
This is because the purpose of the SPARTAN-III project is to create disposableSuper Soldiers that can be sent on high-profile suicide missions. They weren't even issued the MJOLNIR Powered Armor, given weak stealth suits instead. This is what happens to the Alpha and Beta company. The Alpha company is completely wiped out despite achieving their mission goal, while Beta company has a 0.67% survival rate. Also, SPARTAN-IIIs started their training as older kids, and their training was much shorter. This is supposed to be rectified by the SPARTAN-IV program, which is a retool of the original Project ORION (AKA SPARTAN-I) involving "upgrading" veteran soldier to Super Soldiers.
Halo Legends gives us one of the earliest known Arbiters, who manages to carve through an entire Covenant Army with naught but Energy Swords and sheer Tranquil Fury.
And the Halo graphic novel gave us Sergeant Johnson slaughtering through Flood after Flood all on his own... although it's justified since he's actually a Spartan-I and therefore somehow immune to the Flood virus. But the point still stands.
Taken to ridiculous extremes in Drakengard. How ridiculous you may ask?... Well, in around the 10% of the game, Verse XIX "Last War between the Union of Flippedfrance vs the Empire of Notspain", around the first third of the mission Caim has the enemy coundown at 1576... yeah. And this is not the biggest bloodbath in the game and you had probably killed more enemies if you unite the XVIII other chapters. There is a reason why the game is also known as Caim Kills the FUCK OUT of Everybody: the Game
The original one-woman army is probably Samus Aran from the Metroid series. Miss Aran has blown up at least four planets (including a Dark World version of a planet) and wiped out three entire species all on her lonesome. By the end of each and every game, Samus has become a walking instrument of destruction, plowing through enemies with the Screw Attack and able to freeze, incinerate or otherwise decimate every Metroid she comes across. As with the Master Chief, the Space Pirates (her secondary enemy after the eponymous species) are terrified of her and refer to her as "the Hunter" in the Space Pirate Logs found in Metroid Prime and sequels. In fact, in Metroid Prime 2, you can read the journal of a dead soldier who maintains that Samus' exploits must have been exaggerated.
Also in the second installment can be found some humorous logs from the Pirates, once they discover that Samus and Dark Samus are separate beings. "Horrific as it may sound, there are two of them now. We are bracing for a new assault."
"Surely, we are cursed."
The first Metroid Prime also has Pirate logs that basically read, "We gotta find out how Samus's weapons work or otherwise we're screwed!". It gets especially hilarious when they describe certain prototypes, like their attempt to recreate her Morph Ball technology, which tended to horribly mutilate test subjects, crushing and twisting their skeletons. "Science Team wisely decided to end the project after this," indeed.
In the third installment, GFMC troopers will generally treat her as a larger-than-life hero, usually saying things to the tune of, "Samus Aran, it's an honor to meet you!", stopping just short of asking for autographs.
Her Arch-Enemy, Ridley, is a One-Dragon Army. It is implied that Samus is the only person in the galaxy who is actually a threat to him. In Metroid: Other M, Adam Malkovich actually considers him more dangerous than an entire station full of Metroids. Metroids that have had their only weakness removed.
Another example of a One Woman Army is Tanya Adams. Though in Command & Conquer: Red Alert 1 she can only blow up buildings and kill infantry, and only if you specifically order her to kill that infantry, in Red Alert 2, she automatically fires on advancing infantry (with pistols, but long before she's in range of their assault rifles), she can swim even in nearly frozen rivers, and use C4 on ships, buildings, and tanks (in RA2, as with many games, tanks have no machine guns, making them weak against infantry). The only thing that can stop her besides air power and overwhelming force are base defenses like sentry guns and Tesla coils. There are several missions where she takes out entire bases with little backup.
Havoc was part of Dead 6, a crack commando group with specialists for each group. Havoc is basically the jack of all trades, imagine what his teammates would do in their field.
Die, mostly. You fight alongside them for a short time in one mission and can see each of them in action in an earlier mission. The AI isn't all that great, but something tells me that using a rocket launcher or grenade launcher at point-blank range isn't smart. Deadeye is capable of one-shotting any infantry that get in his way, though.
The Nod Cyborg Commando from Tiberian Sun is probably the strongest candidate for this in the RTSes: it's one of the strongest units in the game, bar none. It inverts the usual Crippling Overspecialization of "commando" units by having a weapon that's good enough to destroy tanks and buildings in a couple hits (and it's a One-Hit Kill against infantry and light vehicles), is Made of Iron, can regenerate by standing in Tiberium, and can fit into subterranean APCs for surprise attacks. Ghost Stalker has many of the same abilities for the GDI, except without the Made of Iron part.
Sarah Kerrigan from , who as a human was only a mediocre Ghost (and being the first StarCraft game, you couldn't heal her, making it dangerous to use her in battle), as the Zerg Queen of Blades, she had great armor, huge hitpoints, a melee attack which killed most infantry in one swipe and larger units with 2 or 3, could Entangle from a distance, and could destroy groups with Psionic Storms. During her attack on the Amerigo, when she's ambushed by 20 Marines, she's able to kill every one of them without dying.
Zeratul, the unit with one of the strongest attacks, and also permanent stealth. He also does that in cutscenes. In one mission with proper microing, you can use him to kill half a Zerg base alone.
The sequel has Tychus Findlay piloting Odin, the Super Prototype to Thor. Like Duke, Tychus can lay siege to enemy bases as long as someone provides some healing.
November Annabella "Nova" Terra is one of the most powerful human telepaths and telekinetics in existence. Her telekinetic mind blasts can be measured in Hiroshimas. She's also a well-trained Ghost operative. Too bad her game got cancelled.
Extreme in Roguelike games. In one example, T.O.M.E. (Tales of Middle-Earth), you track down and kill every single Tolkien villain, ever. Up to and including the local equivalent of Satan, Morgoth (Sauron's boss). And then you go To Hell and Back to kill him there. Some versions throw in a few gods and demons from other series, such as the Cthulhu Mythos, Warhammer, and general mythology.
Crawl's monsters might not go up that far in quality, but they certainly don't lack quantity: 266922 creatures vanquished. Also note that this game keeps detailed statistics on how many individuals of each creature type you have killed.
Fire Emblem. At first, you're generally on par with the imperial scrubs. Near the end of the game, though, you'll probably have "that one guy" (or even better, multiple), who you can just throw into a pile of red guys, and laugh at they waltz up and basically get obliterated. It's almost tragic.
In Path of Radiance, there's also Nephenee. The only edge Ike has over her is Aether. Nephenee doesn't need it, because the enemies in most cases are lucky if they even manage damage her at all. If they manage to bring her health halfway down, her Wrath ability kicks in, which boosts her critical hit ratio dramatically, so one hit kills will be served in bulk.
Also, Mia can do serious damage thanks to Vantage. Throw on a Brave Sword, and they all die.
There's also an enemy One Man Army: the Black Knight. Tibarn mentions that he wiped out an entire unit of super-powerful bird-people on his own.
In Blazing Blade, a character named Pent, a Sage, joins as an NPC surrounded by enemies. You want to rescue him immediately, not because he is in any danger but because accessing the sidequest requires your party to gain a certain amount of experience. If Pent is left alone, he'll destroy anyone who dares attack him and steall the experience that you need. He may even end up killing the bosses. Even when he eventually joins you, he is well capable of clearing large groups of enemies.
In the fourth game, Genealogy of the Holy War, you get quite a few characters who can almost solo the very large enemy armies (with the help of terrain bonuses). You'll know them because they wield Holy Weapons.
Seriously, the only reason some of them don't solo the chapter is because legendary weapons only have 50 uses per repair, and there are more than 50 enemies in the game's huge chapters. Otherwise, it's not too hard to win when Levin or Sety wields a Holsety tome with 105% evasion and 60 might.
In Radiant Dawn, there are several. Haar is one of the biggest, along with Caineghis, Nailah, Tibarn, and of course, Ike. However. one man overshadows them all: The Black Knight. Not only is he capable of soloing every single map in which he is available in the game,, he is also the highest possible level from beginning to end. And did we mention that he has what is arguably the second-most powerful weapon in the game, Alondite? And he's also the greatest tactical mind in Begnion, and a major military commander in two countries.
Actually, the enemy has quite a few One Man Armies - the two most-known are easily Dheginsea and Ashera, both of which are completely capable of killing level fifteens in the third tier with ease on easy mode.
With BEXP abuse and a bit of luck, every unit in the game can be one of these, even low-tier ones like Meg and Fiona.
Even the 13-year-old empress Sanaki can rock faces when her speed is upped by 2 or so. Add that to the fact that Flare recharges her health, and all those hits that take her down to 1-2 health are quickly negated.
Sorcerers in Fire Emblem Awakening are very well-suited for this, thanks to two of their strongest weapons restoring half the damage they inflict as HP, along with respectable speed and defense, allowing them to stay alive against the hordes of enemies who will target them and get mowed down by the resulting counterattacks.
The player's character in Neverwinter Nights 2 gains notoriety for this as the game progresses. In addition, a good character will express a feeling of being haunted by the hundreds of dead behind them to a party member in the final act.
Most likely not intended, but the first act involves the player killing, what according to the setting, is significant portion of the eponymous city, who have all decided to join thief's guilds.
If the player joins the theives' guild instead, you'll discover most of those are mooks from out of town. It's still a lot of mooks.
There's even a History Feat that points specifically to this, called "Orcslayer", or something similar. The description says that the "broken remains of the orcs clans curse the day you were born", making it unambigous that you have slain the majority of the orcs of the region.
Deconstructed in the Max Payne series. While Max kills hundreds of criminals in the course of three enraged nights, it causes him severe psychological damage. He also only narrowly avoids going to prison.
Another idolized Player Character is Tact Mayers from the Galaxy Angel gameverse, who, although helped by another fleet, did most of the work defeating Eonia and breaking up the Val-Fasq conspiracy. There is a twist, however—he's a commander and his victories come from the battle plans he gives the Angels, which is a bit more realistic.
Surprisingly, the H-GameMonster Girl Quest has one in Granberia, the world's greatest swordsman, who regularly takes on entire cities worth of guards and soldiers (not in that way) just to prove her mettle.
In Baldur's Gate 2, the protagonist is the spawn of a god, with the potential of ascending to godhood. Quite a few NPC and antagonists are aware of his status and his experience at killing high level monsters, but none are particularly impressed by it. However, in the Throne of BhaalExpansion Pack, an entire nation builds a task force for the express purpose of stopping the PC, and one of the more interesting sequences shows the villain, a high level NPC with multiple monstrous Dragons, panicking at the thought of the PC invading her lair. Even Elminster doesn't want to fight you.
While nowhere near as epic as BG2, being a lower level game and all, the kill count can also get pretty high in the first game. There is one area that is basically a village of the extremely xenophobic xvarts, and if you decide to go through there you'll have to kill several dozens of them. The Big Bad even acknowledges how dangerous you are in his letters to his hired assassins as you kill more and more of them over the course of the game. Also in this game you can meet Drizzt do Urden who is a one-man army in his own right, slicing through hordes of gnolls (and your party, if you are so foolish as to challenge him) without any effort.
In fact, those enemies are actually fairly easy to defeat, so it is claimed. The original trailers made Sora come across as even more badass, with threateningly large Heartless amongst the enemies. Perhaps the thought of it was too much badass for Disney. Sora does, in fact, gain a kill count of at least two or three that over his entire "career".
The actual problem was the severe amount of slowdown caused by having thousands of heartless and then hundreds of Giant heartless on screen at once. This issue was solved during The 1000 Heartless Battle by only allowing the Heartless right up close to you, usually no more than several dozen, to move, and leaves the rest to be rendered as stationary 2D sprites (even beyond the invisible barrier) until Sora gets close to them or there are very few left.
Bonus points go to the fact that, in the upper right-hand corner, you get a kill counter.
Also in Kingdom Hearts II, Sora is able to use his friends as components when he goes into a drive. He becomes this when he goes into Master and Final forms.
In Time Crisis, the protagonist, Richard Miller, is explicitly described as a "one-man army" in the opening scenes. Although his body count is somewhat less than the other examples, he does manage to completely clear out a castle being used as a crime base in about 15 minutes. The rest of the games feature two-man armies.
Spyro the Dragon: the title character in every single one of his games, especially the "The Legend of Spyro'' trilogy. At times he'll have a dozen or more huge, powerful enemies, some with multiple health bars, all attacking him at once, and a minute later they'll all be lying dead.
In Ninja Gaiden for the Xbox and its Updated Rereleases, Ryu Hayabusa slaughters his way through the army of a small empire, starting with their anti-terrorist paramilitaries, then graduating to the conventional army. The body-count is easily in the thousands, and that's not even counting the dozens of ninjas he kills during a training exercise in the first level. If you start counting the demons, then there's easily another coupl'a thousand. The really interesting part is, perhaps, that he takes on a fully-equipped modern-day army—sporting assault-rifles, grenade-launchers, and anti-tank weapons, as well as actual tanks and helicopter gunships—using nothing more technologically advanced than a composite bow. But then, he isa singleNinja.
Super Smash Bros.. Endless Melee/Brawl. You get one life to take out as many enemies as possible. Getting every achievement means you're going to have to take down hundreds.
Nethack's endgame involves trying to sacrifice the Amulet of Yendor to your god and ascend to demi-godhood, which was ostensibly the point of the entire venture. The altars for doing this are guarded by Death, Famine, and Pestilence; War is now the player, what with the massive amount of killing (if not outright genocide) that they've in the process of getting there. And quite goddamn deservedly, considering how difficult it is to pull it off.
This is actually lampshaded pretty brilliantly in-game. The Riders will eventually regenerate when killed, no matter what you do. One standard way to get rid of other regenerators such as trolls is through the use of a tinning kit on their remains. Trying this one one of the Horsemen leads to them springing back to life immediately with the quote "Yes... but War does not preserve its enemies."
You can also #chat to one of the riders, and they'll respond, "Who do you think you are, War?" If you sourcedive, you'll even find the comment "War" == player
Some Roguelikes actually have a feature, genocide, for wiping out entire species. Nethack belongs to this group; the most common way to do it there is using a scroll of genocide, which in it's blessed state can genocide multiple species with one use. As if this wasn't enough, it's also possible for the player to "extinct" enemies, which basically means to genocide manually—that is, kill enough of a particular type of enemy that the game stops spawning them.
On the other side of the coin, it's also perfectly possible of winning the game without killing a single being. This is, of course, a lot harder than the more violent version, but also a lot more satisfying.
Solid Snake from Metal Gear Solid is described by other characters as being one on numerous occasions—but he isn't. It's a stealth game, meaning that if he decides to start Munchkining down the Red Shirt Army he's just asking to be slaughtered.
In Solid Meryl mentions Snake's reputation as a "one man army." Snake insists that he isn't.
Although there's the occasional mandatory sequence in which Snake or Raiden are forced to do just that.
Though they both easily get the one-man army status due to the fact they often have to take down the eponymous Metal Gears (with an occasional Tank or Jet) on their own, regardless of how trigger-happy (or not) they are in the infiltration.
Of course, starting with Metal Gear Solid 2, the player can take the option of a no-kill playthrough. Also technically possible in the first game with the exception of bosses (who must be killed). In fact, based on that information, Snake is either the most genocidal killer ever... or the most pacifistic hero ever.
Similar story with Splinter Cell, where the protagonist is unable to pick up weapons lying around (at least in earlier titles), and must use the limited pistol and silenced gun ammo from the start of the level. He still manages to kill or knock out at least a few hundred people by the end of the game.
Cole Mc Grath from "inFAMOUS". In the first game, he takes on a city full of super powered criminals with nothing but himself and wins. Then the second game roles around and he basically gets MUCH stronger. How strong was he before? Able to call down LIGHTNING STORMS AT WILL.
In Doom, the nameless main character is "too tough for Hell to contain", having slaughtered the entire army of Hell, including an ultra-tough Cyberdemon and a Spider Mastermind. (Of course, the ending sequence reveals that part of his motivation in the fourth episode was vengeance for the death of his pet bunny, so perhaps the experience in the preceding three episodes had unhinged him somewhat...)
Doom 2 takes this further, with the main character out-and-out destroying Hell on his second tour. (Granted, via the death throes of the Final Boss).
Doom 3 downplays the "anything special about him", though; furthermore as a Heroic Mime, his psychological state remains unclear, although in the Expansion Pack you play a different character. Who, er, doesn't even blink when the entire rest of his squad gets annihilated by an artifact which he then carries for the rest of the game...
In Dead Rising, the protagonist Frank ends up responsible for killing thousands of zombies and a handful of psychopathic killers, despite having no combat training. The actual military presence does next to nothing.
True, but he outright states he's never fired at a person.
The most noteworthy achievement in the game requires the player to kill 53,594 zombies... In six hours of gameplay.
For those of you who dont know the significance of that number: It's the population of the Town he's in.
Torque in The Suffering kills hundreds of hideous monsters while fighting his way off Carnate Island, and all by himself outside of the occasional Escort Mission.
In Star Wars Battlefront and Battlefront II, your character is one of dozens of ordinary mooks in large-scale battles. Despite this, the player is expected to rack up enormous kill counts, because the rest of his army is made up of complete idiots. You can personally slaughter over two-thirds of the enemy forces but still have your army lose the fight!
Or it can go completely the other way, and you can be the sole survivor of your army and bring down hundreds of the enemy. And good god, does that feel good.
Inspector Tequila was pretty badass in the John Woo movie Hard Boiled, but in the video game Stranglehold, he truly turns into a One Man Army, gunning his way through... oh, somewhere in the vicinity of 1000 enemies. Ranging from Mooks, to Hitmen, to Russian mercenaries, and everything in between. He also racks up at least 70 million dollars worth of property damage. He basically eliminates three major crime syndicates singlehandedly.
Dante of Devil May Cry has probably accumulated a very impressive demon body count. Lack of clear details makes it difficult to say if he has outdone his father Sparda, who singlehandedly rebelled against The Legions of Hell and saved humanity (or so the backstory claims), or whether the fact that a demon as powerful as Sparda is his father justifies Dante's capabilities, which would make it in his blood.
In certain levels the death toll is in the thousands. Yes, there is a counter dedicated for kills.
Whichever of the three mercs you play as in Mercenaries: Playground of Destruction automatically qualifies, but plot-wise Mattias meets the description best.
Bladestorm The Hundred Years War has this complex, where, at high levels, the main character, even without aid, can destroy a whole army. However, at similar levels, it counters this again, where the protagonist is incredibly weak without men.
The main character in F.E.A.R. kills nearly a thousand genetically modified enemy supersoldiers in less than 24 hours. This feat is made much more impressive by the fact that all of these soldiers are being psychically controlled by one man, so that if one sees you, all the rest know where you are too. Additionally, some of the soldiers wear so much armor that it takes nearly 8 shot gun rounds to the head to kill them; other soldiers are in extremely durable mech-suits. Did I mention that even the basic infantry can take take three 12-inch steel spikes through the head without flinching? The only thing that hero really has going for him is that he has super-reflexes, or from the player's point of view, the ability to slow down time, due to the fact that is his mother, Alma, has psychic/super-natural powers...
The first game also nicely averts the "No one finds this unusual" aspect of this trope with a post-credits phone dialog revealing that the incident was being monitored as an impromptu field test for two experiments: The army of supersoldiers and the player character. Guess which party passed with flying colors?
Even more so in the sequel, Project Origin. The main character is a soldier in Delta Force, a faction that was getting slaughtered in the first game. Yet in the first mission (with no Bullet Time) he kills thirty trained corporate soldiers in as many minutes, gets surgery done to give him slow-mo abilities, and then proceeds to not only kill as many clone Replica soldiers as the Point Man in the first game did (about 500) in the same amount of time, but also to defeat a 500-strong corporate army that could invade a moderately-sized country. Theoretically, he should also have been able to destroy Alma, but this was sabotaged by Corrupt Corporate Executive Genevieve Aristide. The quote from the leader of said corporate army pretty much sums it up.
Mario. Also Luigi in the rare cases where he gets to be the protagonist rather than just a secondary character.
Mario's only a one man army when Luigi isn't with him. Then it becomes a two man army. Moreover, he has been a part of at least 3 four-person armies (all of whom have also included Luigi).
Regardless, he manages to destroy entire fleets of tanks and airships which have cannons, bombs, and flamethrowers on a regular day. The only reason why they're never afraid of him is probably because Bowser is the only one able to match his badassery.
And all they ever need to use? Their jumping ability. The Super Speed and Super Strength come in handy, but they don't really need them to win.
By the end of Resident Evil 4, Leon has singlehandedly killed hundreds of Ganados. When the Big Bad confronts you at the end, it's no wonder he's alone: you've probably wiped out most, if not all, of his army.
There's a note you can find about a third of the way through the first disk, which basically just reads "We gotta do something or he'll kill them all!"
Rayman has often fought entire armies more or less by himself, whether they consist of robo pirates or black lums.
Pretty much any SOLDIER 1st Class from the world of Final Fantasy VII counts. For example, in Crisis Core, one of Zack's first missions is essentially summed up as "Storm the enemy base alone. Have fun." By the end of the game, it literally takes the strength of the entire Shinra standing army to take Zack down.
Genesis is literally a one man army, due to his clones.
The Hero of Fable usually ends up killing hundreds of people and monsters through the course of the game. Since they rapidly respawn and the player can continue the game after the ending credits, the Hero can literally have an INFINITE kill count. Not only that, but every type of being he has killed, and how many, are listed on his character sheet.
Link from The Legend of Zelda hacks up monsters with his sword, shoots them with arrows, blows them up with bombs, tramples them with his horse, kills them in many inventive ways with magic, and in The Legend of Zelda: Twilight Princess, uses an iron ball and chain to massacre them four at a time. In the last dungeon you go through 20 at a time, not to mention cavalry, and in the Hidden Village you have to snipe an entire town of Bublins. In his various incarnations, Link must have killed at least fifteen armies of Mooks, plus their leaders.
That's not even counting the hundreds of bodies one must walk over to complete the Savage Labyrinth/Cave of Ordeals.
However, Link takes this trope literally in The Legend of Zelda: Skyward Sword. After spending the whole game kicking asses, he fights entire armies of bokoblins, on his own, before defeating Big Bad Ghirahim in a duel to save Zelda. And he did it in a row.
In No One Lives Forever, Kate Archer kills hundreds of enemy soldiers in her various missions, and far from not finding this at all unusual, her superiors find it so unbelievable they assume she's lying in her mission reports.
The Silencers from Crusader are described as an entire unit of one-man armies. Given how a skilled player can practically dance through levels and has probably killed thousands of enemy troops by the end of each game, it's not that much of a stretch.
By late-game, Altaďr of Assassin's Creed I is literally hacking and slashing his way through entire armies of Saracen and Crusader troops.
He may be a mortal man, but he surpasses Determinator status at the speed of light and lands squarely into Implacable Man territory.
In Revelations, we see what decades of studying The Apple of Eden can do. Altaďr's fights were never exactly close, but killing a village full of soldiers all at the same time is a gamebreaker in the most awesome sense of the term.
In Assassin's Creed: Brotherhood this actually becomes moreso the case, even before he cuts or sneaks his way through one more army to confront Cesare Borgia for the last time. It's possible that the first potential recruits were actually inspired by him openly fighting off Borgia troops across the bridge/river from the papal apartments.
Even his recruits get into the act once promoted to the highest rank, Assassino, at level 10 — Smoke Bombs + Pistol + as many Health squares as the final boss = the Call Assassins button becomes an "I WIN" button against most Mook groups.
The trope is called attention to at the start of Brotherhood.
Ezio: Checking up on me, Uncle?
Mario: What can I say? We sent one man against an entire army. I was worried!
And in the intro of Assassin's Creed: Revelations, Ezio (who is by that point in his 50s) taking on a regiment of Templar soldiers by himself... after taking an arrow in the shoulder. True, they manage to capture him, but only because he gets a vision of Altaďr at precisely the wrong moment.
Assassin's Creed III continues the tradition with Connor, who is depicted in the E3 trailer taking on an entire British regiment by himself in order to assassinate their commander. In so doing, he rallies the Continental troops who had up until that point been suffering a crushing defeat. To this end, Connor has developed skills specifically designed to help him deal with massed musket fire, including taking cover during volleys and using the bodies of his enemies as a Bulletproof Human Shield.
He doesn't actually kill that many people in the trailer (less than a dozen). He just creates so much chaos among the enemy ranks (including slaying the British general) that the American counterattack manages to succeed. Then again, the trailer ends before the battle is over.
Over the course of the series, Desmond gains the skills of his ancestors via the Bleeding Effect. By the end of the third game he takes on the entirety of the Roman branch of Abstergo by himself, limiting himself to knife and gun before revealing that he has complete control over the Apple now.
Assassins Creed IV focuses on Connor's grandfather Edward Kenway, a notorious pirate with a penchant for Dual Wielding swords and strapping four pistols. As detailed by Blackbeard in a trailer, he has once seen Edward clear the deck of a Spanish galleon like it was nothing. This can also apply to Edward's ship the Jackdaw. With proper upgrades and proper sailing, the Jackdaw (a converted Spanish brig) can easily take down a man-o'-war or two.
Averted in Snatcher, where Random Hajile is considered highly skilled because he's managed to hunt down four Snatchers in a month.
In the Metal Slug series, the Mooks will often run screaming from the player character, and for good reason—they currently have three wars with the Rebellion Army, two alien invasion attempts, a demonic attack, and an invasion from the center of the earth on their list of things defeated. Notice that the game plays trope literally: The player doesn't simply blast away Mooks and other infantry, but indeed, takes out dozens of tanks, combat helicopters, bombers, fighters, battle armors, ships, stationary guns, and, of course, the bosses. Of course, the game being on the far side of silly side, it is all depicted in a most comical manner.
Lampshaded in Up Your Arsenal: Once Ratchet shows up on the battlefield in Veldin, all the front-line soldiers take the Genre Savvy approach by tossing him their guns and getting the hell out of there.
Probably the most literal demonstration of this trope occurs in A Crack in Time, in which there's a level where Ratchet goes back in time to single-handedly win a war just so he can get a ride off the planet when he returns to the present.
Which then gets drained from his body in the second game. Of course, he then goes from One Man Army to One Man Apocalypse.
By God of War III it's been stated that if anything was left alive, it's because Kratos hasn't killed it yet.
Ashley Riot from Vagrant Story doesn't need reinforcements... he is the reinforcements.
Almost hits the trope by name: "Gods... is he even human? He fights with the strength of a brigade..."
This is what the Riskbreakers like Ashley were trained to be. There's never more than one of them sent on any mission, because one is always enough.
In the original Star Fox and its N64 remake, the Big Bad controls a massive war machine aimed at conquering the Lylat System. The freedom-loving Cornerians are hopelessly outmatched and outnumbered....until they call upon the help of the Star Fox team. Flying in a small squad of ultra-advanced Arwing starfighters, Fox McCloud and his 3 teammates lead a daring counterattack against Andross, obliterating hundreds upon hundreds of enemy craft, destroying entire fleets of battleships, and defeating numerous boss enemies. Turns out the teammates don't even contribute much, it's all the player-controlled character carving a swath of destruction through the Mook army.
In Video Game/Starfox 64, the Star Fox team presents their "fee" (kill count) to the Cornerian army for their services. Depending on how high the number is, General Pepper has reactions ranging from "It was worth it," to "WHAT!?!"
Guilty Gear's background material indicates that Potemkin, resident Mighty Glacier, is estimated to have such incredible physical strength and stamina that he is as dangerous as an entire armored division. Considering his One-Hit Kill attack involves him punching someone once without his strength inhibitors, that seems justified.
The game Astérix & Obelix XXL, despite having two characters, pretty much embodies this trope, as Asterix is the one you play as most, and thus he is the One-Man Army, while the significantly stronger Obelix is AI-controlled and isn't exactly that useful. In the very last section, you also have to take down 1000 Romans.
By that point in the game, you should be able to purchase a special attack that enforces this trope even more: it transforms Asterix into a powerful tornado, sending literally hundreds of Mooks flying. Just one or two of them can wipe these armies.
Disgaea 3 has Princess Sapphire Rhodonite, who effectively serves as her kingdom's entire military force.
In a cutscene in the first game, Laharl personally takes on the EDF invasion fleet, numbered in the millions, and wins.
From a gameplay standpoint, it's practical to create one of these, due to level differences not factoring into EXP calculations. There's also an ability bearing the trope's very name, which doubles the unit's stats when they're the last one available.
Possibly first played straightest in the original Dragon Quest. An entire nation's military force is overrun by enemy mooks, and one man, with no weapon or armor, no equipment of any kind, and no magic (well, at least he starts that way) steps up and singlehandedly slaughters thousands of monsters and the big bad himself.
In Crysis your suit makes you a One-Man Army. A slightly more realistic one than usual, because you can't carry more than three weapons and you do die with surprising ease if you fail to notice the grenade that has rolled near your feet or if an enemy scores a lucky headshot, but in the end you still manage to defeat untold numbers of baddies all by yo'self.
You don't even have to use weapons to be a one man army. You can just use your Good Old Fisticuffs to literally kill a hundred KVA troops. Theoretically, this also works on aliens, but their strong close combat capabilities make it really hard to do.
In Saints Row, you played as a custom made character who had to take down three rival gangs, mostly by yourself. Somewhat subverted in the fact that you can take along members of your gang with you on missions, and they could wield the same weapons that you do, but doubly subverted in the fact that they were exponentially weaker than you and could not take as much fire as you. In the end, it takes a planted bomb to off you.Saint's Row 2, however, confirms that your character is still alive.
Taken to to it's peak with Saints Row The Third, where the player, being the boss of the Saint's, takes down a multinational criminal organisation, stops a zombie outbreak and even tears apart an army equipped with sci-fi level technology created for the single purpose of stopping the Saint's. Depending on the ending you get, the boss tops all of his previous achievements by destroying a massive flying aircraft carrier.
Nariko of Heavenly Sword becomes a One Woman Army, especially toward the end when she's singlehandedly taking down literal scores of King Bohan's men in a truly epic War Sequence before the final showdown.
In Painkiller Daniel literally plows through thousands of demons occupying Purgatory, kills the generals of hell (who all range from 3 to 5 stories tall) and battle your way into hell and kill Lucifer. Yeah it's part of the story and thus a spoiler, but really how could you not see it coming?
Tony Montana from Scarface: The World is Yours can easily get over a thousand kills to his name by the end of the game, and that is without actively farming kills from respawning enemies.
Ninety-Nine Nights. Every level is The War Sequence, and you're the one who kills just about everything in sight. Oh! With a modicum of help from the two regiments that accompany you into battle, but really, they don't do a whole lot.
Terra of Final Fantasy VI is introduced in the opening segment as a one-woman army who "Fried 50 of [the Empire's] Magitek-armored soldiers in three minutes".
Immortal Defense had your ascended character slaughter thousand of ships and everyone on board in the eons long defense of your dead homeworld.
Amaterasu in Ōkami. Oh dear kittens, Amaterasu. Granted, she is a goddess, but still, she ploughs through monsters as if there's no tomorrow.
Deconstructed in Iji. If you decide to kill everything in sight like is expected in other games, you end up fighting off TWO CONSECUTIVE ALIEN INVASIONS IN ONE DAY. You actually get awarded the rank "One Woman Army" if you rack up 300 kills by the end of the game. The alien's chatlogs grow noticeably more afraid, and there is a You Bastard moment if you go this route. On the other hand, it is also possible to go through teh game without killing a single enemy, which leads to a somewhat happier ending.
The game doesn't ignore the psychological impact that the war has on poor Iji. She isn't a soldier, she'd never killed before the start of the game, and she's reluctant to start fighting in the opening cutscene. During gameplay, she apologizes to the first few aliens she kills, then grows silent as she gets numb to it, then when her kill count gets high enough, she starts screaming "Die!" at her enemies, in a voice that sounds like she's coming unhinged.
Mitsurugi in the Soul Series is a mercenary who explicitly sides with the outnumbered sides to fight more people. Even explicitly mentioned in his good ending in Soul Calibur III: "If you want to kill me, you had better bring a whole army."
Yet even he is outdone by Nightmare, who completely annihalates a huge army of Knights in the opening of Soul Calibur III. In his weakest state.
The protagonists of the two Knights of the Old Republic games have a decent go at this—the Jedi Exile, in the second game, massacres her (canonically, the player can choose the character's gender) way through an enormous battleship (with a little help from the boss Mandalorian and the battleship's owner's (reformed?) Sith apprentice) before single-handedly carving through the entire population of a Sith academy, wheras Revan storms through much of a giant Sith-powered army factory to confront his traitorous ex-apprentice.
Darth Malak rather Lampshades this in a flash of Genre Savvy. He tells to send all his troops to confront the PC, not because they'd be able to stop him/her (of course they can't), but in order to give him time to prepare his defenses.
On that Star Wars note, Kyle Katarn from the Dark Forces Saga, who has killed quite a large number of the Empire's servants and other miscreants in his journeys.
There's a reason the EU establishes him as the new Jedi Battlemaster by the time he gets into the books.
His apprentice Jaden Korr almost singlehandedly destroyed a conspiracy to revive a dead ancient Sith Lord, then (re)killed the Sith Lord Marka Ragnos.
Isaac Clarke of Dead Space, a single engineer armed with six power tools (plus one real gun) who takes down dozens and dozens of the creatures that wiped out and recruited an entire ship of over a thousand people, along with four separate gigantic monsters, one of which was technically invincible. In fact, he not only fails to die, he performs way better than the actual soldiers who turn up later in the game!
In Dead Space 2 he does it while fighting the government and insanity, In Dead Space 3 he does it while fighting depression and an environment trying to kill him.
Conqueror: 1086 AD asks the player to do a lot of castle storming. You can assemble an army and storm with a healthy collection of nights and bowmen. Or you can do it your damn self. The latter option is more efficient.
In Shogun: Total War you could build kensai units. Whereas other units represented groups of soldiers, this unit was a powerful single swordsman. So powerful that if you placed him at a choke point (so he couldn't be flanked or surrounded) he could take out whole units on his own.
The Marathon series is another example, and perhaps one of the first games to try to justify this trope. The character goes from being listed as just another security officer, to being a military super cyborg, to being the hero with a thousand faces, until the game decides the only possible justification is you being the physical embodiment of destiny.
Durandal himself. The Pfhor sent the best fleet (14 ships, 10% of the active navy) commanded by their best admiral. He destroyed half of them with a single stolen Corvette before going down, and then finishes the job when he hijacks the flagship.
The nameless pilot protagonist of Einhander is explicitly described as being feared in the opening cutscene, and if his backstory exploits even approach those made while beating the game, why he has that reputation is aptly demonstrated.
The power of the God Hand allows its wielder to pimp-slap the entire legions of Hell all by his lonesome.
Legendary Champions in Dwarf Fortress, especially ones with particularly well-made hammers, unless crossbows are involved. They tend to have godlike statistics, move like thunderbolts, and can hit goblins so hard they crash into trees and disintegrate in a spectacular spray of limbs. Legendary champion marksdwarves are in many ways even scarier, because DF crossbows in the hands of sufficiently experienced troops tend to function like a fusion of sniper rifle and heavy machine gun. Incidentally, the history of the randomized worlds will sometimes cause entire armies to start fights with solitary "historical figures". The odds are disturbingly stacked against the army.
This is taken to the extreme with Morul, who is currently legendary in 68 out of 73 skills. Even crossbow-wielding orks are no match for him.
Mention must also go to Tarn Adams for being a One Man Army of Developers. Seriously, Dwarf Fortress has far more content than almost any two or three games you can think of put together, and one guy made the whole damn thing.
In a very rare RTS example, World in Conflict can have this. An ordinary unit of 5 soldiers can take cover and fight ridiculously well against more enemies, with bad cover. One time while this player was playing Cascade Falls, a unit took cover in the ruins of a house and held off most of the Soviet army until a hydrogen bomb was dropped on the nearby town.
The main quest of The Elder Scrolls III: Morrowind involves becoming Hortator, or "War Leader" of the three Great Houses, suggesting that you'll be leading armies into battle... not really. You'll breach the main fortress of the Big Bad on your lonesome (if you follow Vivec's advice, after sacking the enemy's other fortresses first, equally on your lonesome).
Likewise, the Dovahkin in Skyrim can wander the countryside alone or with a single companion/packmule/arrowcatcher and clean out fortresses, bandit camps, ruins and crypts of anything remotely hostile. Your follower may be a valuable supporter early on, but eventually they'll just slow you down (and possibly get in the way of your shots). And that's saying nothing of the fact that you're the first TES protagonist to treat firebreathing dragons as random encounters.
Although that last bit is a tad misleading, since the Dovahkiin is also the first TES protagonist to have the opportunity to treat firebreathing dragons as random encounters. It's not the fault of the Eternal Champion, the Apprentice, the Agent, the Nerevarine or the Champion of Cyrodiil that they lived in times when dragons were really, really rare and did their best to keep to themselves (even in Cyrus' time, dragons were rare — and the dragon Cyrus faced and managed to bring down was of a colour that Skyrim implies is quite rare and only found on the most powerful of dragons).
Actually one could infer that The Remnant of the Dragons at those times were among the weakest members, hiding because the ones that caused trouble tend to get hunted down. Dawnguard and Dragonborn revealed that while Naafililargus was an Ancient Dragon, there are actually several more powerful types of dragons out there. He also had a habit of forging truces with mortals for protection, so either he wasn't a good fighter to begin with or was drastically out of shape when Cyrus fought him.
The vast majority of arcade games made by Capcom in the 1980s and 1990s fit this trope. For instance: In 1942, a single P-38 tries to shoot down the entire Japanese air force (in later sequels gameplay was also expanded to include sinking the Japanese navy). In Gunsmoke a lone gunman goes pistol-to-pistol with hundreds of outlaws, pistol-to-arrow with an entire Indian village, and even pistol-to-shuriken with a ninja squad. In Final Fight, one brawler (two if you play with a friend) picks a fight with a huge criminal gang who have kidnapped the mayor's daughter and have an entire city completely terrorized. In Ghosts 'n Goblins, a solitary knight confronts an army of demons, undead creatures, and eventually Lucifer himself to save his princess. And in Commando, one soldier (named "Super Joe" even though he doesn't technically fit the Super Soldier trope) becomes quite literally a One-Man Army; armed with nothing but a machine gun and a handful of grenades, he has to fight his way through a jungle swarming with an endless number of enemy soldiers, with a few hostages to rescue along the way. There are lots more of these types of games in Capcom's library, many of them sequels or Spiritual Successors of the originals.
Alex Mercer, from Prototype. You even regularly get updates on how many military, civilian, and infected you've killed during the course of the game, and it very, veryrapidly goes up into the thousands.
There is an Achievement for killing 53,596 Infected.
BioShock's Jack Ryan—who fights his way through Rapture directly after surviving a plane crash, destroying at the very least four heavily armored and powerful Big Daddies at the ripe old age of two! That said, he was designed that way...
Mark Meltzer from the Something in the Sea ARG, who is just another ordinary man who didn't know the existence of Rapture until his daughter, Cindy, was kidnapped by a Big Sister. He fought his way through Rapture armed with a revolver and came very close to saving his daughter
Booker DeWitt from Bioshock Infinite. Before he even meets Elizabeth, he kills at least a hundred trained police officers/soldiers, a few of which with his bare hands, in the span of mere hours. By the end of the game, the casualties are easily in the thousands. The extremity of his rampage is even lampshaded toward the end.
Booker's backstory mentions that as a teenager he fought at the Battle of Wounded Knee, where his rampage was so brutal that he's very likely the reason it's known today as a Massacre. Despite being praised as a "Hero" by his fellow soldiers, he was absolutely horrified and disgusted by what he had done.
The Lone Wanderer of Fallout 3 can become quite the killing machine, capable of wiping out squads of raiders, mercenaries, and government soldiers with little more than a beat-up hunting rifle. This is especially intriguing given the character was raised for nineteen years in a totally sterile, controlled environment. Of course, your dad did give you a gun at age ten...
Of course, the Vault Dweller and Chosen One of the previous games can do much the same thing and one was also raised in a sterile controlled environment.
In Fallout: New Vegas there are three in game challenges that net you a few extra experience points and a small bonus to damage. "Lord Death," "Lord Death of Murder Mountain" and "Apocalypse Ain't Got Nothing On Me." The first requires 200 kills. The second requires 700 more kills (for a total of 900 kills). The third requires another 1000 kills (for a total of 1900 kills). They seem appropriately named.
Also, the Soldier went on a Nazi killing spree on his own during World War 2 and didn't stop until he learned the war was over in 1949.
In the "Meet the Medic" video, the Medic and Heavy are a two-man army (close enough, right?) when the Heavy is ubercharged. They kill so many Soldiers as a team that they can pose on a pile of them at the end of the video.
Whoever you play as in Diablo or Diablo II. In the first game, you venture into the depths of hell killing every demon, critter, and monster in your path including Diablo himself. In the second game, not only do you plow through Hell and kill Diablo, you also kill his brothers Mephisto, Baal, and legions upon legions of their evil minions, all by yourself. It's a virtual one man demonic genocide.
And in Diablo III? You and your companion get to save both Sanctuary and the High Heavens from Belial, Asmodean, and eventually Diablo himself!
The original Mega Man was upgraded from a humble assistant into a one man army to fight against all of Wily's robots.
Mega Man X has fought multiple robot wars all by himself. Zero and Axl eventually join him as partners, but they're all one man armies themselves. After Zero and Axl are sealed/disappear, he's a one man army again for so long that he eventually gets sick of it and retires.
Sonic the Hedgehog could count as a one hedgehog army, of sorts. As particularly depicted in Sonic Unleashed, he regularly annihilates entire armies of robots, leaving them smoking piles of metal in his wake.
The power trios that make their first appearance in Sonic Heroes count as three-man armies of sorts; especally prominent in 'Egg Fleet' and 'Final Fortress' in which they're more or less pitting themselves up against a large, heavily-armed fleet and winning. Considering that at least one of the teams is composed of an ornery killer robot, a government agent, and a guy calling himself the ultimate life form, and several of the other teams go toe-to-toe with them throughout the game...
Shadow was essentially created to be one. Every game he's been in usually has him single-handedly taking apart entire armies of humans, robots, aliens, etc, all in the same day. What makes him more dangerous is that he doesn't refrain from killing.
Galen Marek is trained for years by Darth Vader to hunt and kill surviving Jedi while leaving no witnesses, and boy does he deliver. By the end of the game, his kill list includes two Jedi (plus two who "merely" soundly defeated, and possibly the phantoms of three more (and it should be reiterated that each Jedi is a One-Man Army in his/her own right)), hundreds of soldiers, stormtroopers, aliens, and assorted scum, several AT-STs, a friggin' star destroyer—plus several more, indirectly—and (in the bad ending) Vader himself! (Even in the good ending, he soundly defeats Vader and has him at his mercy!)
This happens a lot in EVE Online. Various missions involve destroying wave after wave of ships. Depending on the level of the mission this can vary from dozens of frigates to dozens of battleships. It is implied in the lore that aforementioned battleships have several thousand crew members, so one mission could have a kill count in crew members that runs into the multi-millions fairly quickly. It's also worth knowing that EVE players are Capsuleers, they use capsule technology which seriously reduces the need for crew numbers. NPC's don't have the advantages that come with capsules.
Rubi Malone from Wet is another one woman army, taking out a couple of criminal gangs, and about two thousand mooks over the course of the game.
In Cave Story, the protagonist destroys the Demon Crown (an Artifact of Doom granting its wearer insane power) and the island's Core (apparently a powerful conduit of magic); both of which had destroyed armies of combat robots in the past. And as an encore, in the good ending he's joined by Action Girl Curly Brace and the two of them kill the sorcerer who created the Demon Crown.
In The Godfather: The Game, you can expect to run up at least 250-300 kills taking over Little Italy for the Corleones. If you have less than 1000 kills by the time you become Don by toppling the other four families, you're doing it wrong. In the sequel you have assistance from a Badass Crew of Personal Mooks but nothing's stopping you from keeping them all in reserve and going to town on NYC, Florida and Cuba by yourself. Even with their assistance you're still taking on several times your number regularly and winning.
And then there's the simpleminded Dwarf lad who is good at enchantment. Near the end of the game, while you're Storming the Castle, you come across him standing in the middle of about two dozen dead demonspawn. What does he say when you ask him what happened? "Enchantment!"
In Dragon Age: Origins the Grey Warden and his/her allies can accrue a very impressive kill count by the end of the game. Since the Grey Warden is required to be in the party for most of it, chances are good that he or she will rack up the lion's share of the kills. It's even lampshaded in one sidequest after you help beleaguered guardsmen kill an entire band of mercenaries and their leader notes that only an idiot would willingly attack you. One poor dwarf who tries to attack you at one point even says that you fight like an Archdemon. There is an achievement for killing 1000 darkspawn over multiple playthroughs. It is entirely possible to earn it in one playthrough. That does not cover everything else you kill. By the end of the game you and your small band of companions will have killed legions of enemies.
Every Grey Warden is chosen specifically because they are Bad Ass. A dwarf in Orzammar will tell you that only Grey Wardens go into the Deep Roads without a squad of soldiers at their back. In the Dalish Elf origin, you find Duncan by following the trail of darkspawn corpses left in his wake.
In Dragon Age II, when most city-states have a problem, they send an army. When Kirkwall has a problem, they send Hawke.
Lampshaded by Varric in the case of fellow party member Anders, whom Varric claims has killed about 500 men, 250 women, and some huge number of giant spiders. And he's the party's resident healer.
Jack, from Madworld, is able to kill hundreds (maybe thosands) of people including bosses that have better weapons, some that are monstrously enormous, a giant robot and even some that can regenerate using only the environment, his strength and a freaking CHAINSAW on his arm. It's later justified as Jack is actually the former Grand Champion of Deathwatch.
The USS Cheyenne from Tom Clancy's SSN is a One Sub Navy. Of course, it does have a serious technological advantage. This is acknowledged in the novelization, where the captain is promoted to rear admiral and receives both the Congressional Medal of Honor and the Order of Mao Tze-Dong.
Lampshaded in Starlancer. While the player himself doesn't receive any special recognition beyond a few medals, his squadron are described in one news broadcast as "seemingly hell-bent on winning the war all by themselves".
The distant sequel Freelancer, though, subverts the previous game by revealing that the Alliance-Coalition war lasts for another 100 years before the Coalition ultimately wins, no matter how many enemy ships the player's squadron has eliminated. Played straight in Freelancer itself, where Trent can single-handedly destroy enemy battleships in a one-man fighter.
Commander Shepard & co. in Mass Effect. One of the dialogue options before the final battle against Saren is:
Saren: Commander Shepard, what took you so long?
Shepard: I had to wipe out a few hundred of your followers.
Just about any powerful biotic qualifies (take Jack, for instance, who immediately after being brought out of cold storage proceeds to tear a space station apart with her brain).
Garrus is another noteworthy one - he spent a long time killing hundreds of mercenaries all by himself. Granted, he had a severe advantage in terms of environment, but still.
Lampshaded in Mass Effect 2. On the Korlus mission, you are going through mercenaries like a hot knife through butter. Said mercenaries are an interstellar private Badass Army: during the mission, they get sandwiched between the Normandy crew and hundreds of berserk tankgrown krogans: by the last third of the mission, you can hear them saying that they got rid of the krogans, but desperately need reinforcements as Shepard's unit is slaughtering them with ease. Eventually, their leader chastises them on the intercom:
Jedore: There are three of them! Three! Anything can be killed if you do your job!
Shepard was this by him/herself in the War Hero background where s/he held off an entire platoon by him/herself until reinforcements arrived thus saving the colony that s/he was defending.
The SSV Normandy is a one-ship armada by the end of Mass Effect 2. This is even quantified in Mass Effect 3, where the military contributions of military forces are expressed in terms of numerical "War Assets." Entire fleets of hundreds of frigates and cruisers and multiple dreadnoughts and carriers contribute about one hundred to one hundred and fifty points to the total each. The Normandy, by itself, contributes one hundred and fifteen points. For comparison, the Destiny Ascension, the massive dreadnought that served as the Citadel flagship in the first game, provides 70.
Similarly, squadmates from Mass Effect 2 and some of the ones from Mass Effect 1 can be added to the War Assets pool. Potentially, adding squadmates to the war assets pool can net you an additional two to three hundred points, which can exceed the value of the entire ground force components supplied by some species. Only the krogan, all of the Alliance ground units you can recruit, and possibly the entire geth corps can supply more effective combat strength than ten of your squadmates.
Even more badass than Shepard's squadmates are the N7 Special Ops. A single promotion is worth a whopping 75 points of military strength, and while the entire class category's level is reset when you do this, the fact that you don't gain more points the more characters you have in that category effectively implies that those 75 points are from one person - and this assertion is backed up by the game mechanics. So one operative is worth more than the Destiny Ascension by themselves - and this isn't even getting into how multiplayer is the way most players build up their Galactic Readiness. (a statistic that can double your effective military strength if maxed out)
Every asari commando is a one-woman army. They are considered to be the deadliest fighters in the entire galaxy (with the exception of Shepard), and even the codex says that going up against one alone is practically suicide. This is perfectly summed up by the War Assets entry for the Serrice Guard, a unit of asari commandos. After a space battle with a Blood Pack ship, they and the Blood Pack were forced to crash land on a planet. Over the course of nine days, the Blood Pack suffered over a hundred casualties from traps, ambushes, and night assaults. When the Blood Pack gave up and finally surrendered, they found out that they had only been fighting FIVE asari commandos.
And then there are krogan battlemasters. On two occasions, we hear about battles between an asari commando and a krogan battlemaster. One of these battles ended with both dead; the other ended in a draw... and the space station they were on destroyed utterly.
Even more than the Normandy, each Reaper is a one-ship armada. Even the weakest Reapers take massive barrages of artillery or ships firing down on them to destroy them. It's implied that a Sovereign-class Reaper is a match for three of the most powerful non-Reaper ships in the galaxy.
And Sovereign isn't even the largest Reaper. That would be the Harbinger. Sovereign is the Reaper equivalent of an advanced scout.
Borderlands if you're playing solo: You'll easily rack up the ten thousand corpses required to get the "I am become death" achievement.
In Alpha Prime, your Mission Control speculates that you might be The Mole when he points out how unlikely it is that you could have defeated so many enemy soldiers unless it was all staged.
"And don't say they want to kill you. Those boys keep plugging away, but somehow they still can't seem to finish the job. They can't seem to shoot you properly. It's a pure miracle you're still alive. And miracles are always suspicious."
Though not canonical examples, Parker and Mason, from Red Faction and Red Faction: Guerrilla respectively, end up appearing as one-man armies, considering how hideously incompetent the rest of the Red Faction seems to be. The Red Faction wouldn't have got anything done if it weren't for those two.
Your character from Def Jam: Fight For New York. Think about it for a second: he so dominates the underground Fight Clubbing circuit that he takes over a bunch of the bad guy's fight club locations on his own. This continues until the bad guy suggests a winner take all match to settle everything. After you win that fight, the bad guy goes back on his word and takes most of those club locations back by force, but that's ok because you can kick his goons out of all those clubs and reclaim them. Then after all that, when the Big Bad declares that He Has Your Girlfriend, you turn back around an retake all those clubs from the "good guy" gang by kicking their butts for the Manipulative BastardBig B Ad. So, basically your character will singlehandedly destroy two huge criminal gangs by himself, with his bare hands, in the course of maybe a couple of months. Oh, and for fun during his offtime, he can get into and win various independent tournaments and battle royals too.
In Supreme Commander the player is literally a one man army. Gate technology only allows small amounts of mass to be teleported, so commanders are teleported to the battlefield where they build and command the actual, robotic fighting force.
Jack Carver of Far Cry deserves a mention. Enemy mooks speculate about how one person could not possibly pull off the stunts he does. However, his Genre Savvy allies Val and Doyle both expect and demand that he be a One-Man Army on a regular basis.
In Pokémon it is possible to play throughout the whole game with a single Pokémon. Simply use one Pokémon for battles, and others for useless HMs.
Made impossible in Black and White, where Pokemon gain less experience the higher level they are compared to their opponent.
The player character, who defeats the region's local evil organization pretty much alone.
In Perfect Dark, while stealth is generally encouraged (and at times forced), Joanna is such a good fighter and so much more durable than her opponents that it's equally possible to simply blast the enemies and still win the missions, so long as said mission doesn't actively require you to avoid alerting or shooting guards.
Suikoden II has Luca Blight. In one army battle, your team sets up an ambush to try and take him down with their entire goddamn army. They manage to pin him down even wound him. Then he gets angry. The battle ends after that with your characters expressing relief that there weren't as many deaths as they expected.
In game, to defeat him, you have to make 3 groups of characters to attack him, and ever after the three fights, you have to defeat him in a character duel. All of this after he is struck with an arrow.
'An arrow?' AN ARROW? By his death, Luca has taken five barrages of arrows (each arrow apparently being strong enough to one-shot his elite guards which take multiple character's attacks in-battle to kill). He ends up dueling The Hero with at least SEVEN arrows still stuck in him. And he can STILL kick your ass. Better remember to keep the Hero healed up before going into the duel.
While something you'd generally want to avoid in Mount & Blade, when you pull it off you feel like the biggest badass on the planet. Nothing like single handidly slaughtering a two-hundred man army by yourself.
For those who are unfamiliar with the game, becoming an actual One-Man Army (against actual enemy parties which number around 50-150 on average) is a VERY difficult feat. You start off far weaker than every other soldier out in the world. And even by end game, you will only be as best as the elite soldiers that other vassals can easily recruit in the hundreds. Even on the easiest difficulty, charging down a group of 5-10 elite troops is no easy feat. On 100% difficulty, attempting to take on any more than 3 enemies at a time is just inviting trouble, and taking on 10 toe-to-toe would be plain suicidal. The closest a player can get to being a One-Man Army is by focusing on archery and defending castles from above during sieges.
Or horseback archery, which, with patience, a good aim, a very fast horse, and a bit of luck to dodge the enemy projectiles, allow you to take down armies.
This troper was able to hold off entire armies alone by standing slightly to the right of a ladder during a siege and then swinging at head level for an hour or so.
Lampshaded in Revenge of Meta Knight, where as you go through the game taking out every enemy and destroying entire sections of the ship you see the conversations between Meta Knight and his men, with them starting off mildly annoyed you get on board, surprised at the damage you do, then finally deciding to fight you honorably before going down as Meta Knight himself says nothing but "...Thank You." As if they were a small fleet being taken down by an actual army with no way out.
In Myth 2 Alric the Emperor of the Cath Buric can take on an entire army with the help of a magic sword that shoots fricking lighting out to strike down his enemies, in fact it's suggested that you let him be a one man army considering that the lighting can kill your troops to. when he's not wielding that sword he has a magic spell that jumps from enemy to enemy blowing up each one. Once you run out of spells you still is unbeatable in single combat. His evil counterparts are even more badass emphasis on bad. By using the level editor with Myth 2 you control soulblighter who is invincible to all but alric's attack's. Balor soulblighter's predecessor is once again invincible with the added bonus of calling lighting down out of the sky. shiver has a range of spells well suited for taking out an army but not invincible. And the the deceiver can brainwash an entire army and does in one level.
Valkyria Chronicles introduces an enemy called Selvaria, a Valkyria soldier who can crush an entire squad of soldiers without backup. The first time you meet her, the only thing that's safe from her is a tank, and said tank most certainly cannot damage her, as she can deflect anything it fires at her, and this whole thing is exacerbated by the fact that you're fighting a MASSIVE TANK with SIX MACHINE GUNS on it at the same time. The NEXT time you meet her, even the tanks aren't safe, and the mission becomes a mad dash for the enemy camp while desperately trying to slow her down before she can destroy your base camp. The third time you meet her, she's lost her invulnerability and tank-killing powers, but is so fast the only hope you have of hitting her is sneaking up behind her, and her range has increased so that she can hit almost ANYTHING on the map. Later, Alicia, one of your units, becomes one of these too, and, while generally slower, she's powerful enough to beat Selvaria in a 1 on 1 fight, then proceeds to rip apart the enemy forces without breaking a sweat.
Taken to extreme levels when you consider that she wipped out several battalions of Cocoon's finest soldiers, the Cavalry, without any visible effort or breaking a sweat... and this is after dealing with an entire security fleet back on the race track without any visible effort either. Hell, even as a mere human she managed to wipe out an entire train of soldiers effortlessly. Final Fantasy XIII-2 seems to have taken this even further as she is not only stated to be far beyond that of a L'cie by the director... she now COMMANDS her own Eidolon army, commands an army of feral beasts, regularly defys the laws of physics, shatters entire buildings with a single spell, slams enemies through entire buildings, is immune to time manipulation, and now channels her magic to use as bullets.
Snow also counts, considering he curbstomps and entire army battalion midway into the game.
Featured in the classic Star Raiders: the only person who can stop the Zylon fleet and protect the galaxy's scattered starbases is you.
Star Wars: Rogue Squadron for the N64 has the player character essentially doing all the killing while your wingmen are useless. The sequel on the GameCube at least has your wingmen look slightly more useful rather than flying around in scripted paths, but One Man Army comes back big time in one of the final missions where you must take on two Star Destroyers by yourself. Instead of a combined assault with friendly fighters, bombers and capital ships (which would, you know, make more sense) it's all up to the player to knock out these massive warships by himself while his allies fly around doing whatever. See also the "TIE Fighter" example above.
In Heroes of Might and Magic IV, one of the many gameplay changes from the three first ones was that your heroes could walk around on the map without an army. The skill system was revised, and made your heroes able to actually fight on the battlefield instead of their earlier, supporting role. The result of this? Any level 20 hero with Grandmaster Combat, Melee and Magic Resistance combined with Expert skills in Life Magic could defeat small armies without the help of creatures. Ten levels and some additional skills (Archery, another Magic skill or more Life Magic) later, they wipe out entire endgame armies singlehandedly.
In the first campaign, the description before the last battle with the Big Bad has Lord Lysander go into battle against about 10,000 skeletons and the evil hero. The story is told from the viewpoint of his squire, who is wounded by an ambush and is unable to aid his lord. The squire sees in amazement as Lysander takes out the Gryphonheart Sword, something that only one of Gryphonheart bloodline can do and personally slaughter all the skeletons, destroying the false Gryphonheart Sword and capturing the Big Bad.
Alan Wake in, well, Alan Wake. For a novelist who never fired a gun outside of a shooting range, he is impressively adept at gunning down the Taken. It turns out, however, that he gained this ability by literally giving it to himself. Thanks to the supernatural effects of Cauldron Lake, everything he wrote as part of his novel "Departure" came true - and he wrote himself as the novel's protagonist who faced hordes of Taken and barely survived.
Geneforge heavily features minion magic and summoning. The Agent and Servile classes can both become capable of surviving without them.
This is the point of the titular Geneforge. In the first game it takes your nearly endgame protagonist and, if you use it, gives you ludicrously improved abilities. Your shaper no longer needs to shape; you can take up glaring enemies to death. In later games you're Geneforged in the very beginning because both sides of the war need super-soldiers and aren't picky about how they get them.
Geralt of Rivia. If you stick with his True Neutrality at the end of the game, by necessity he becomes one-man-two-armies.
Asura takes this to higher levels, taking down enemy after enemy like no tommorow, from massive buddha mooks, to PLANET SIZED DEMIGODS.
After that, the second boss is much harder.
Artix in DragonFable. In a war with 100 million undead, he killed 50 million alone and felt he was ripped off when the thousands of other heroes killed the other 50 million.
This occurs in the "Conflict" games, "Desert Storm" and "Desert Storm II: Back to Baghdad". In these two games, despite having a team of four highly-trained and specialised soldiers - a rifleman, sniper, heavy weapons specialist and demolitions expert/engineer - players were capable of completing each mission of the games with just the heavy weapons specialist, Mick Connors. His skill with a light machine gun and anti-tank weaponry, coupled with the game's auto-aim system, bottomless backpacks, and more than enough ammo to supply an army in each level, made Connors capable of carrying out every mission he appears in solo. Though he would need to be given mission-dependent equipment from his comrades such as C4 and designators at the start of each level.
This is lampshaded in Conflict: Global Storm (aka Global Terror in the US), where in the training level Control comments that "With the possible exception of Connors, no soldier is a one-man army".
Still, the very first level in the Campaign of Global Storm begins with the player assuming control of just Connors, who, despite being captured, beaten, and tortured, manages to overpower one of his captors and single handedly secure the small prison his team-mates are being held in - optionally with just a combat knife!
In Makai Kingdom, the titles for the second to highest tier infantry units is "One man army" and "One woman army" respectively. (The highest is "Lethal Weapon".) Since you cannot have more than eight units on the map at any given time, and since some areas (dungeons) require you to go through up to a hundred maps before you can return home and rest/resurrect/save, having a team of unstoppable and untouchable battle monkeys is essential if you want to go forth and bust a cap.
The Admiral Proudmoore from Warcraft III, even without his bodyguards is capable of killing thousand of orcs, trolls, ogres and taurens.
Broxigar in the Warcraft: War of the Ancients trilogy of books, specifically the last one. He goes out in a blaze of glory against Sargeras after having killed dozens, maybe hundreds, of demons.
Rico of the Just Cause series is about as close to a literal example as you can get, since he routinely waltzes into military compounds and casually slaughters dozens of solders in between blowing up various important structures, until he gets bored and steals a passenger plane so he can crash it into a police squad. Not for the sake of a mission, either; the game encourages you to wander around randomly blowing things up and mowing down the countless mooks that try to stop you.
The Kid from Bastion hacks his way through multiple small armies over the course of the game.
Stranger the Bounty Hunter in Oddworld: Stranger’s Wrath. Although it’s optional as to whether enemies are dead or not, Stranger still bounties a heck of a lot of Outlaws. It’s taken even further when Stranger is outed as a Steef, meaning that greater amounts of enemies are now being thrown at him due to his bounty, and suddenly there isn’t as much pressure to keep enemies alive anymore...
Player characters in Star Wars: The Old Republic are frequently given missions that they're told, point blank, they're being asked to do because it's too dangerous to send the army to handle it. Literally: "That factory is too well defended for our troops to take - go kill the garrison and signal us when it's safe to come in and occupy it." It's especially common on Balmorra. It could be said to be technically averted—you're generally not fighting alone after the first half of the prologue unless you specifically send your companion away. That being said, you do pull off an awful lot of stuff for a two-man team... While it's to be expected even in-universe that the Jedi Knight and Sith Lord characters would be one-man armies (that's what Jedi and Sith are), the trope applies just as much to the Badass Normal characters. Particular note should be paid to the trooper on Ord Mantell, who unlike most other classes has to take on the big final mission of their starting planet's arc solo.
The backstory of Chaos in Dissidia: Final Fantasy is that he was supposed to be Onracians' answer to another country's One-Man Army, Omega. Then he was driven insane by power and devastated the world, or something. By the time the game starts, it takes several Armies of One from other worlds to take him down.
Special mention among said Armies of One goes to the Warrior of Light. Meta-wise, he becomes an Army of One by being a Composite Character and due to the... interplay between Dissidia and Final Fantasy I it is implied that now FFI is cleared by a single character. In story, he faces more non-Mooks than any other character, alone, in the ending to 012 fights an entire army on his own until he can no longer stand, and in the Alternate Universe of Scenario 000 is stated to be the last one who fell to Feral Chaos.
In Kingdoms of Amalur: Reckoning, entire bandit gangs, cults, and squads of Tuatha soldiers fall to the Fateless One. The Fateless One occasionally has some assistance but still does most of the work. Of course, the Fateless One isn't just a Badass, he/she is a Badass who can wield the fabric of Fate itself as a weapon. The "House of Valor" questline pits the Fateless One against increasingly ridiculous and unfair odds, with the audience expressing amazement every time he/she wins.
In Xenogears, Id is able to take on Gears by himself. When he's in his own Gear, he destroys entire armies.
Not just armies. He destroys entire nations. And it's alluded to several times that he wiped a continent off the map at some point before the start of the game. You never actually beat Id...but that's because the main character eventually discovers that he is Id.
In Star Ruler, military strength is tied to more things than numbers alone. Therefore, a lone mega-battleship can be worth fleets of lesser craft.
Agents from Syndicate, both the originals and the remake. In the original, one to four Agents under your control can mow down any number of police and enemy Agents similarly equipped as themselves. In the remake, Miles Kilo and the Wulf Western Agents can also scythe through entire units of Faceless Goons, as well as Agents equal or superior to themselves.
Pit in Kid Icarus: Uprising, a hordes of monsters and even a God can't defeat one Pit with a Weapon of Choice. Palutena does have more of an army than just him, but they're unreliable and so she usually doesn't bother sending them out.
Jason Brody in Far Cry 3. In a bit of a subversion, even with all the health upgrades and body armor, he's still extremely vulnerable, so he achieves victory through trickery, deception, and tactics. Deconstructed his ability to inflict death drives him closer to insanity.
Hotline Miami: A double subversion like with Uncharted above. You're a One-Hit-Point Wonder like every last mook, which makes your ability to scythe through them by the dozen all the more impressive.
Warlords Battlecry 3 offers you both a race with which to build a base and an army, and a hero with which to either help the first, or to send them against the enemies. A high level hero built with the latter in mind doesn't need a base at all, killing even titans all by themselves.
Common army units can gain levels as well, and though it doesn't reach the extent outlined above, a level 10 unit is a nightmare, even if it's just a normally weak slime, skeleton or pikeman.
Joel and Ellie in The Last Of Us may not rack up the kind of insane body counts that Nathan Drake has, but they still manage to kill an impressive amount of foes, especially considering that the game they're in tends to be quite a bit more realistic than most others.
In the 2013 reboot of Tomb Raider, Lara transforms into one over the course of the game. Especially noticeable during the final stages of the game, when she's confronted with and plows through an army of undead samurai warriors.
The PCs of the S.T.A.L.K.E.R. series. Sure, you're far from bulletproof, but over the course of a single game you'll rack up a bodycount nearing the quadruple digits just from the main storyline, let alone all the extra murdering you'll do for gear, side missions or for fun. You'll face mutant wildlife of several flavors alongside hundreds upon hundreds of brainwashed Monolith troops, zombies, bandits, and any member of any of the factions you've pissed off, which can possibly include both Duty and Freedom, two of the largest factions in the Zone.
You can start proving the Marked One's status as a OMA within five minutes of starting the game, by taking down an entire car park full of bandits and rescuing a captured rookie Loner with (most likely) nothing more than a leather jacket and a Makarov pistol. The guy who offers to go with you calls you an idiot when you tell him to stay back, but is amazed when you actually do it. Later on, you clear out at least one military-held base, raid a bandit hideout and kill their leader (and probably everyone inside), and blast your way through a checkpoint held by the Monolith.
Mini Robot Wars has several one-bot armies, but Leonid(The Shooting Hero) stands out. He fires at a really fast rate for Gunner Bots & can shoot in all directions. With the gatling gun upgrade, the machines might as well start waving the White Flag.