Skoll of Cry Havoc has a body count of a paltry fourteen. Take note however that four of those kills were with a sword against assault rifles and shotguns. Three more were the crew of a main battle tank. That she charged down. As it fired every weapon it had. And hit her. Suffice to say, she worked for those kills.
Pick any member of the main cast in Chaos Theory. Each of them can dish out epic destruction in their own way.
Connor hacks into a security system to make people get killed by their own defenses.
Kevin drops explosives everywhere, leaving mostly rubble and singe marks.
Troy literally punches out tanks and wields an AA gun like a pistol.
Karnak in Dominic Deegan by necessity. It's noted he doesn't really seem to gain or keep followers very well, so any battles he ends up fighting, he pretty much has to do it on his own. Being the single most powerful demon in Hell by this point certainly helps.
In one of the latest arcs, we see a battle. On one side, Demon Siegfried and a gigantic battalion of demons. On the other hand, Karnak. The tagline? Two armies clashing.
Jacob Doe in Genocide Man has taken on large groups of both wannabe bioterrorists and professional soldiers with nothing but his augmentations and a handgun (granted a full-auto railgun with sarin-tipped darts). It's said that Genocide Men are designed to take on armies. Later on, the real psycho among the Genocide Men (who got his WMD-level plague-dispensing failsafe pack taken away because he kept triggering it for fun) casually slaughters an entire city by hand, its denizens helpless to stop him, to draw Jacob out. If you want an idea of how that same "real psycho" (named Joey) was back when he still had that plague dispenser, just check this timeline. As a summary, the body count he so often brags about is of at least 400000 people.
Girl Genius, being set in a world of mad science, has plenty.
Zeetha is a one-girl army, killing every one of the pirates that abducted her, then blowing up their fleet, then blowing up their base - all while recovering from an illness that had made her sick for weeks and given her hallucinations. Also an example of Did Not Think This Through - she forgot to leave any alive to ask them where her homeland was.
Also, any strong Spark with little preparation can be an enormous trouble.
Goblins has Kore, a very badass and very evil paladin who has apparently wiped out armies of orcs and ogres single-handedly.
Any high-level gosunote A "gosu" is someone who is an expert at something. In this context, "gosu" refers to a martial arts expert. from Gosu qualifies including, but not limited to, Gang Ryong, Sa Paecheon and Soh Jinhong.
An example of Gang's might was most notably highlighted when he effortlessly ravaged an entire faction as well as one of its elites in a matter of minutes.
Guilded Age: While a complete douchebag and all around jerkass, Payet had taken on literally hordes of enemies single-handedly without so much as a split end.
Shogun from Harkovast kills what is literally a small army of Nameless warriors. To make matters worse, about half way through he pauses to announce that (despite having him ridiculously outnumbered) THEY are the ones who are all going to die.
Almost every single notable character in Homestuck; however Jack Noir takes the cake, who lights a planet on FIRE, and casually destroys at least 15 more as well as later destroying an entire universe from the outside. Even before he go he got powers of a First Guardian, he was qualified as this - right after he get powers of the the Black Queen and King, he proceed to end the war between Prospit and Derse by singlehandedly slaughtering both armies.
The legendary swordswoman Meti once fought ten thousand men, completely naked, with only a single sword. She won.
Meti's pupil, Mathangi Ten Meti Mantra, also known as Murder The Gods and Topple Their Thrones, is able to kill boatloads of people in a district-sized gang war without standing up from her bar stool at a noodle vendor, or even turning around to them. With a broken sword.
The big ones, though, are Roy, V, and Belkar. Between strips 917 and 924, the three, in rapid succession, face down an entire army. First Roy, effectively alone, with hundreds of arrows raining down upon him, as well as thousands of incoming soldiers, proceeds to speak confidently about surviving for hours until dusk- and then starts making good on that statement. As he's slowly overrun, though, V comes back from Hell] sets up a Wall of Fire around the protagonists, putting the attacking army on the defensive. Then, as the fires begin to lie low, Belkar hijacks an Allosaurus and proceeds to rip the entire army to shreds with it.
Worth pointing out though that Belkar is a nuanced example: he cuts through lowly Mooks like a hot knife through butter because his Dexterity is very high (so he can jump around slicing people up like Yoda) but conversely his other physical stats are subpar and his mental stats, particularly his Wisdom, are abysmal. His record against higher-level opponents is one of the worst and spellcasters in particular tend to steamroll him.
At first, Elan had no notable fighting capabilities at all, but after becoming a Dashing Swordsman, he's definitely getting there, and can now hold his own against multiple foes. In strip 918, he actually tries to invoke this against Tarquin's army, but unfortunately, since Tarquin is Elan's father, they refuse to fight him out of fear.
After alien Santa's army was wiped out, he casually took the field alone and demolished half of Halloween.
Nightmare from Sidekicks proved how powerful she was when she effortlessly annihilated the countless Alex clones that attacked her. To put this in perspective, just three of said Alex clones were able to overwhelm another superhero only moments before.
Skin Horse: Unity is an undead supersoldier created by the US government. She's been known to eat bombs, accidentally break through twenty feet of concrete, and fight off small superhuman armies. When a four-star general throws troops at her, Unity thanks her, and her friends just sit by to watch the carnage.
Dr. Lee:[thinking] This was the vision in my mind, long ago. The beautiful nightmare: Now it looks upon me with leaden eyes. She is a poem of perfect violence. She is my shining Enyo, my radiant Bellona. Soldier: HOLY MOTHER OF— [explosion] Officer: GUNSHIPS! GUNSHIPS TO CHESIRE NOW! Unity: Aw yeah, it's on. Sweetheart: Yeah, I remember the first time I saw Unity do a client intervention. Tip:I'm gonna get a soda. Anyone else want a soda?
In Super Temps that is main character Skully in a nutshell. Her powers allow her to decimate any threat so well that she has to hold herself back. If she went off the deep-end at any point, mass destruction and chaos would ensue!
Several characters in Tower of God, especially Zahard's Princesses like Yuri and Maschenny, High Rankers like Yu Han Sung and Ha Jinsung as well as Zahard and his 10 Great Warriors. For them it is already at the point of subversion because what they are able to do has reached a terrifying notoriety.
Ha Jinsung showed just why he is ranked in the Top 100 when he stormed his former pupil's secret hideout and annihilated all of the guards without so much as breaking a sweat.
Then there is the case of Irregulars, those whose presence violates the basic rules of the Tower. Mostly because they were able to open the doors to the Tower themselves, they are among the most powerful beings in the Tower, so powerful in fact, that they are either the highest ranked Rankers or go even above that. Urek Mazino was able to climb the Tower in around fifty years, 10 times faster than average, and even overwhelmed Arie Honnote The strongest Great Family head. before becoming a Ranker. Enryu killed theGuardian of the 43rd Floor, even though they were considered practically immortal and unbeatable. And finally, Phantaminum appeared out of nowhere, stormed Zahard's castle, killed hundreds of High Rankers in his way, reached Zahard and decided, for some unknown reason, to leave again. In the end, there was no choice but to make him the highest ranked of the Tower.
On a smaller scale, Ja Wangnan convinced Baam to make a truce with him because even if he was strong, he wouldn't hold out against the next six contestants. When the rest arrive and start squabbling, Baam decides to fight them all and nearly beats all but Wangnan, whose lucky skills and PokéBombs save his ass.
Schlock Mercenary has several members of Tagon's Toughs able to defend themselves against larger forces, but two stand out:
Schlock is a Blob Monster that can increase his mass as needed (usually by pouncing on and eating his opponents), and uses various BFGs as personal handguns. Or an occasional Jet Pack, in the case of the Plasgun.
Kevin is the ship's munitions commander, and is considered "the encyclopedia entry for Mad Scientist". His rank insignia epaulettes have been turned into two variable-yield antimatter grenades; one storyline showed that "warhead" might be a more appropriate term— one was a shield-breacher tank killer, and when someone ask why they were running away from the other like it was a nuke, all his captain would say was "If only..."note The second grenade had been accidentally armed during a firefight, his company was trying to run for "minimum safe distance", and the explosion knocked down a ship as collateral damage. Remember, this is a rank insignia epaulette. Then there was the time he had to be enhanced by nanite-boosts to take down an enemy fortress....