In Tekken, the use of Eddy, Yoshimitsu (and Christie in newer games) is often bemoaned by opponents and audience as the repetitive and fluid nature of their attacks leaves little room for counter-attacking.
In higher levels of play these issues disappear, only to be replaced by certain other elements. The most prominent example of a formidable character was Jin in T4. While every Tekken has had tiers (even the most balanced game to date, Dark Resurrection), the main problem was that Jin's Laser Scraper move timed in a certain manner, in addition to his various ways of keeping pressure through frame advantage (he would recover faster than the opponent in various situations that were easy to bring about) caused him to be head and shoulders above the rest of the cast. Other than perhaps the console-only Jinpachi in DR (and even this is debatable), there has never been another character to be the sole occupant of the top tier level.
Jin's grandfather Heihachi was pretty ridiculous in Tekken 5 though. Most of the time, Tekken operates on a punishment system where moves that net low reward allow retaliation that also nets low reward if blocked or dodged. However, one of Heihachi's jab combos was fast enough to punish an opponent's low reward move with damage equal to most character's main juggle combos, when most character's jab combos did a fraction of the damage. Simply put, if a character could normally get a 15 to 20-damage point combo (comparatively low reward) in retaliation, Heihachi could get a 66-damage point combo (out of 144.5 total health on a Tekken character's lifebar). What made it worse was that the combo was three moves long. See 1:09 of this video.
Steve was also another ridiculous character in Tekken 5, being the only character with an infinite. This infinite is based on his left sidestep/sway into body blow, it is very easy to land the first hit while dodging the opponent's attacks at the same time, and puts the opponent in a perpetual stun when done repeatedly. Worse yet, the move was safe on block.
Law's backflips are a spamwhich because he always does two in a row of higher difficullty levels. Law also has plenty of moves which launch you up in the air, just so he can string some backflips and juggle you.
Eddy is a Button Masher character. The ease of creating constant dancing combos means that a blind five-year-old could easily beat you if you don't know exactly how to avoid the flailing legs. Even his Idle Animation makes it hard to hit him.
For Gon, by holding + (), you can unleash a killer move that almost kills your opponent. Because Gon is small and fire-proof, he is especially dangerous.
The usage of Bob in Tekken 6 is extremely frowned upon. He is so far above everyone else with his fast, god-priority attacks that he is the sole member of S-tier in the game.
As of Tag 2, there is no top tier. There is only "Mishima Tier", because every single Mishima (Kazuya, Heihachi, and Devil Jin, in that order) dominate the top tiers due to their insane juggles, tag combos, and damage output. Jinpachi, despite his original status as an SNK Boss, has been completely rebalanced and is not considered a Game Breaker because he is not a "traditional" Mishima (he does not possess his successors' wavedashes and has a different variation of the Electric Wind God Fist).
Street Fighter I has the Shoryuken, which deals 3 hits, each of which takes off a third of the opponent's entire lifebar. 3 * 1/3 = 1 full lifebar. Oh, and the attack is unblockable. In other words, get all of those hits to connect and it is an instant KO, even if the opponent is guarding for their dear life. You getting acquainted with the command means you can pretty much murder the entire single-player campaign.
The use of Akuma in Super Street Fighter II Turbo tournaments is banned, thanks to his immense damage and combos he has in that game. Subsequent games he appeared in have Nerfed him to the point of being a Glass Cannon, and he has now become a balanced character whose presence is welcomed quite emphatically at Street Fighter IV tournaments.
In the Super Street Fighter II Turbo HD Remix, he was toned down so that he could be another playable character, but the end result of these changes was that he ended up gaining several overpowering juggles, as well as an unblockable air fireball trap which can lead to a loop. Yes, he turned out even more proficient than he already was. Thus, Akuma remains banned.
Old Sagat (O. Sagat) in SSF2T (the Super Street Fighter II version of Sagat who can be unlocked in Super Turbo) is an example that sits on the edge. He's not outright banned (meaning you won't be stopped from picking him) but is still a potential game breaker. Much like the Jin Kazama example above, O. Sagat's outrageous projectile recovery enables him to lock his enemies down with ease. Because of this, and in the interest of tournament diversity, he's "soft banned" in Japanese events (meaning that the players collectively agree to not pick him) as otherwise, the game would be so heavily skewed towards his usage and would likely monopolize the character selections for all participants.
In Street Fighter IV, did you want to tackle all of the AI challenges without ever breaking a sweat? Zangief. Double Lariat. Repeat et nausium. You're welcome.
Guilty Gear tournaments traditionally ban the characters Kliff, Justice, and (depending on the version of the character) Robo-Ky.
This is not because they are game breakers per se, but because they were added in console versions as bonus characters without taking the time to balance them with the rest of the cast. Exactly how broken or not-broken they are is debatable, but the community, not wanting to take any chances, chose to pre-emptively ban them. The same principle applies to the EX characters, alternative versions of regular characters that are gradually unlocked in the console versions.
The tier list for Guilty Gear XX #Reload is usually defined in this fashion: Low, Mid, High, and Eddie Tier. Yes, Eddie completely dominates the entire cast with his godlike unblockable setups with his shadow attacks, as well as the ability to dizzy any character in just 2-3 combos.
In Accent Core Plus, Eddie reclaims his top-tier spot, but now shares it with Testament and Slayer.
Duo Lon was once banned in The King of Fighters tournaments, until he got his infinite combo taken away in KOF XI.
Also, Choi. Virtually all viable options, setups and combos are rendered obsolete because of his size.
The King of Fighters '95 features Omega Rugal and Sasyu Kusanagi, the game's boss characters, as unlockable characters. Unlike other examples of this, where the boss characters are Made of Plasticine when playable for the sake of balance, these two are not toned down at all compared to their boss versions.
In '98, we have Goro Daimon and Iori Yagami. Goro has a variety of odd glitches that make him an absolute monster, and Iori capable of just about any type of play style you can imagine. Not to mention Iori has had the same infinite in almost every one of his appearances.
Said "Goro infinite" bug was removed in Ultimate Match, placing Goro back into a more complacent spot on the tier list. However, Iori was practically unchanged, and he had Geese and Krauser join him in the top tier. Expect to see teams consisting of these three a lot.
Ralf Jones from The King of Fighters EX2: Howling Blood on the Game Boy Advance. Remember his Galactica Phantom HSDM from the main series? The horrifically lethal, yet easy-to-dodge charge punch? Well, he has it as a normal move in this game. It does less damage—only 50% of a lifebar—but it has a much much shorter charge time, meaning you can actually use it and connect most of the time, it gained some anti-air priority AND it's still unblockable/puts Ralf into autoguard mode for its duration. Needless to say, spamming that move makes playing as Ralf fall somewhere between Easy Mode and outright cheating. It actually makes fighting the final boss somewhat even, which is saying it all.
Raiden in arcade versions of King of XIII. His dropkick combos pretty much kill any other character. And they destroy 75% of your guard meter on block!
In the home versions, which updated the game to version 1.1 and rebalanced everyone, one change being that Raiden's dropkicks now have a much longer charge time, making all of his overwhelmingly effective setups and combos impossible.
Soulcalibur III has several moves that cannot be easily parried or blocked by the game's AI (different from the designated unblockable attacks, which are too slow to put to any real use). Hardcore gamers consider them cheating, but considering a CPU opponent in this game can actually block front attacks while his/her back is turned, many players have no qualms whatsoever about cheating back.
Soulcalibur's Nightmare had a two-hit strong, strong default combo. If the first hit missed but the second hit, the result had quite a tendency to instantly catapult your opponent off the stage. Then there was Maxi, who, while you couldn't do much against the cheating AI with him, allowed most unskilled players to demolish more or less any human opponent just by pressing buttons at random and fiddling with the joypad. No wonder he stayed dead.
Talim's back-A move first strikes high, then low, and if it hits, the opponent gets knocked down. It's quite easy to force the opponent to the edge of the arena, use the move, and knock him off.
Some weapons in Soulcalibur II, believe it or not. Back then, use of certain weapons had special effects tacked onto them, such as increased damage, range, and even speed.
Most notably, Mitsurugi's Damascus Sword and Yun-seong's Han Guang, both of which had extremely long range, longer than even Kilik's staffs.
Ivy was pretty close to game-breaking when used by a competent player in Soulcalibur II. She had the longest range in the game, sweeping attacks to hit sidesteppers, and excellent knockback / blockstun to keep opponents at a range where they were useless. She also had a fast, mid-hitting ringout kick (back+ K) for when an opponent's back was to the edge, a ringout THROW when her back was to the edge, and another powerful ringout kick (fwd,fwd+ K) if the ring edge was to her left.
Hilde in Soulcalibur IV has a string that almost always guarantees a ring out, while not devastatubg per se, the general annoyance of fans at the move is such that players who were doing it were loudly booed in Evo 2009. Nowadays, she's banned from tournaments. Fortunately, in Soulcalibur V, they wised up and removed the combo entirely.
A balance patch, however, has given her an infinite...which simply involves using her charged B attack, then charging up again for the level 2 version, and once the opponent is overhead quickly turn around and use the attack again. Fortunately, the use of this infinite has been banned until such a time where Namco can patch the game once more.
One of Link's basic throws in the GameCube version of SCII. For games versus actual people, not terribly useful, but for the Weapon Master mode, a complete gamebreaker, since most games in that mode can be won by ringouts, which are easily accomplished using this move, since you can ringout your opponent with your back to the stage edge.
Yun-seong. Fast kicks, heavy sword attacks, long combos, and the most annoying piece is one of his most basic attacks that is endlessly chainable and attacks in a high-then-low pattern. Unless you've learned how to parry and know when to use which height, it can get really annoying. But considering he is mid-tier.
Xianghua has any number of move that can be easily abused, but in the third game her guard-breaking spin move has her go in low and fast with a guard break move that has basically no recovery time AND the move had tracking, so your opponent can't side-step the move at all. On top of that the lack of recovery time allows you to get a second hit in that will knock down your opponent and then you can follow up with another one that will hit them on the ground. and even after that you can follow up again as your opponent gets up and hit them since the move covers a decent amount of distance and has tracking, an opponent trying to get back up has little to no chance of dodging it.
Nightmare in V had this status. It is fairly easy to ring people out with him, and once he gains momentum there are only a few ways of putting a stop to his extreme rushdown tactics. However, he is no longer considered this...
...But someone has taken his place. Enter Viola. Just when you thought her tactics involving setting crystal balls in mid air and hitting you from odd angles were annoying enough already, renowned fighting game renaissance man Tokido claimed at an MLG tournament that he had "hidden technology" to show at EVO that he believed would force Namco to patch the game. That "technology" was an extremely effective and great infinite involving Viola's back throw. With careful inputs, Viola can use her back throw to constantly reposition her opponent towards the edge of the ring, or simply keep doing it over and over until the opponent just gives up. The use of this infinite is now banned.
Naruto: Gekitou Ninja Taisen! 4 generally bans the use of Akamaru (the dog) since most characters have an extremely hard time hitting him, due to his small size and fast speed.
Akamaru isn't the only one. One-Tailed Naruto, Cursed Seal Lv. 2 Sasuke, and Itachi were HUGE Game Breakers. OT Naruto has a grab attack that stretches and catches the opponent from across the stage. Itachi could send out Clones that attacked from a distance and could teleport. Some fans complained they'd "Nerfed" Itachi, among with several others in the Sequels.
There's Sasuke in the Shippuden games, where he has an easily spammable attack that can be repeated nearly infinitely.
Bando can be considered one, incredibly fast, powerful attack, long range attacks which can stun opponents easily, as well as the fact that he can use a special that prevents flinching, he takes damage, but that problem is taken away in that he can land hits on you while you're attacking.
As of the third Shippuden, the Power Levels have gotten to the point that every character except Neji and Shikimaru has at least one move that would be considered a Game Breaker in a normal game—it's a bit like if Brawl Minus were a serious project. Even among this elite, however, the three characters who have invulnerable allies in combat (Kiba with his dog, Kankuro with his puppets, and Chiyo with her (different) puppets) are considered overpowering compared to the rest. Kiba is particularly horrifying thanks to a glitch that allows him to keep Akamaru's leap primed no matter what, even while taking damage. This makes an even halfway competent Kiba utterly impossible to do anything to, as the dog tracks and will always knock you out of anything you might attempt; furthermore, his cinematic also comes out incredibly fast and has near-perfect tracking, making for godly wakeups.
Mortal Kombat Trilogy had Noob Saibot with a terribly powerful infinite combo which involved his disabler projectile that prevented the target from making hostile contact with Noob, allowing the player to thrash away with his pop-up combo, his insanely easy and abuse-happy kick combo and sending out hyper-fast clones that lift the opponent in the air. Not to mention his Teleport Grab.
All you had to do with Noob Saibot is use his No-Block ball to prevent your opponent from blocking, then press low kick, low kick, low kick, low kick. Seriously, it's that easy. You could execute this combo twice before the effect of the No-Block ball wore off, making most fights a joke. This combo even ownedShao Kahn, and pretty every other fighter except Motaro because he was immune to projectiles.
When using Quan Chi in Mortal Kombat: Deadly Alliance you use the "grab" move, in which Quan Chi jumps on the opponent's chest and bashes them several times in the face. After this, they fall to the ground. Time the next grab move right and you can repeat this until the opponent sinks to the ground unconscious, since there's a brief moment while standing up in which it's almost impossible to block.
Speaking of Deadly Alliance, Frost. Ground Freeze. Uppercut to Ground Freeze. Uppercut to Ground Freeze. AGH!
Mortal Kombat 2 and Kitana's ever-infamous Fan Lift. Notice how nearly all infinite comobs at least require a series of precise attacks in quick succession? Here's Kitana's: Retreat to corner. Jump over enemy, crossup jumpkick. Fan Lift. Advance a bit. Then casually mash high punch while the hapless foe is juggled into oblivion with no way out. (This absolutely owned Kintaro and Shao Kahn, to put it in perspective.) It was so stupid, in the update, Midway limited Kitana to one punch after a Fan Lift, the only time in my memory they had to put a lid on a basic attack.
The arcade version of Mortal Kombat 3 gave us Nightwolf, who could run faster than someone being thrown. Yeah.
Not to mention he had one of the quickest projectiles with virtually no lag time afterwards, and he could reflect other character's projectiles back at them.
Kabal. Good God, Kabal. He's so fast that he could probably beat up everyone in the Black Dragon AND the Red Dragon on his own with only a Run button as a weapon. Nightwolf's throw combos got nerfed early in vanilla Mortal Kombat 3's life cycle, but Kabal kept running circles around everyone else all the way to Trilogy.
Stryker has to top the list for biggest game breaker in Ultimate Mortal Kombat 3. Why? Because that was when Midway decided he needed More Dakka. Once that got introduced, all someone playing as Stryker had to do was stand far away from his opponent and go back, forward, high punch until the opponent died. No wonder he was a Creator's Pet.
Stryker was always combo happy even before he obtained the use of his gun. One popular chain for those who actually played him was to pop the opponent into the air with a HP, HP, LP combo and then use the Nightstick Flash (F, F+HK) move while the enemy was airborne to toss them to the other side of the screen. Then while you are trying to get to your feet the Stryker could Nightstick Flash again to get close and repeat the whole process. If the Stryker was more forgiving then they could just lob a grenade in your face.
In the original Mortal Kombat, if Sonya managed to land a Leg Grab, she could repeat this move infinitely until her opponent's health ran out. To make things worse, the grab was unblockable.
In Mortal Kombat X, as thesevideos show, Quan Chi (Sorcerer variation) can exploit a loophole that allows him to cast more than one spell. This grants him him a permanent increase in Scratch Damage (to the point that they're more deadly than if they're hit unblocked) and give him almost permanent Super Armor, as well as granting him as high as 100% damage combos. This, however has since been patched.
You want to talk about cheap in Bleach DS? In the Japanese version of the first game Kenpachi Zaraki has a special that makes him invincible for its duration and teleports him in front of the opponent. It can be repeated immediately when it ends unless the opponent is airborne. This can be used as a perfect defensive counter against nearly anything, and he can switch to attacking as soon as it's safe. Never mind that his one super stock which gives a buff that almost guarantees half the opponent's life in damage when it connects. Said super also serves as super cancelling move that can cancel pretty much everything you do, most notably a part of your special moves to extend combos, and OTG's or Wallbounces. It also reduce damage scaling, AND disallows damage cancelling. This translates into Zaraki's simple poke(which is pretty good) leading into a nasty, massively damaging combo. To make matters worse he also has a Rushing Slash that gives Super Armor and Wallbounce. In addition to all that he has an invisibility special that offers a nasty mind game, and when combined with all his other moves you know what can or will happen.
In another Bleach fighter, Shattered Blade for the Wii, there's Uryu Ishida. The only character in the game with a naturally ranged weapon (which tells you something already), he has exactly one move that doesn't involve hitting from a distance - instead, it pushes you away, where he could resume hammering you with guard-breaking power shots. A halfway-skilled Uryu player could also make use of his special delayed-release arrows to attack and defend at once. And that's not even counting his Super Mode, which throws in Flash Steps and gigantic lasers.
Also on Shattered Blade, we have Sosuke Aizen. Again. Bear in mind that specials are performed by holding the B Button, and swinging the wand of the wii remote vertically, horizontally, or in a stabbing motion. Sosuke Aizen's stabbing special is to negate any enemy attack by releasing Kyoka Suigetsu, and immediately performing an unblockable counter. This can be performed Ad Infinitum, meaning you can win a match without taking damage.
Soul Codes in Heat the Soul 6 are quite effective. Neliel's nullifies projectiles, Zomari's gets rid of your opponent's partner, Aizen's restores your Reiatsu at a higher rate, and the list goes on.
Marvel vs. Capcom 2 has Storm, Cable, Magneto, and Sentinel, who are so powerful that fans refer to them as the "four gods". These fight have a high amount of infinite combos and exploits that completely destroy the rest of the cast. To make it even worse, there are over 48 characters in the game, most of whom are either nearly useless in comparison or effective only as assist characters.
As far as Cable goes, four words: "AIR HYPER VIPER BEAM!!!"
They are also projectile specialists who excel in long-range, which was how to own that game. Many an expert player call up a team of Cable, Gambit, and Cyclops, then beat the story mode without ever having to leave the left side of the screen until Abyss.
There are also the characters that tend to never show up except as assist characters, but kill the fun for new players just as much: Cyclops, Captain Commando, and Psylocke, whose dominating assist attacks make up for their mediocrity as point characters.
Strider is also seen paired with Dr. Doom as an assist to execute a devilish trap which can keep the opponent in perpetual blockstun, rendering them unable to move while they take chip damage. As an added bonus, unlike many characters who have dominating assist attacks Dr. Doom is considered a High Tier character in his own right.
Iron Man has all sorts of nasty tricks, in addition to being Magneto Jr. There's a good reason why he's High Tier folks. Blackheart does some nasty shit as well.
Tron Bonne's projectile assist is glitched as well and does more damage than the programmers intended. Because of this her assist sees some tourny play.
Sentinel looked to be one again in Marvel vs. Capcom 3, due to his high health, high damage, high range, high amount of super-armor frames, fast dash/wavedash, good air maneuverability, amazing projectiles, assist moves, and easy combos. Luckily, there are a few anti-Sentinel strategies being created to exploit his weakness to rushdown (His slow attack startup makes him weak at extremely close ranges), but Sentinel was a massive threat until...
... A patch that decreased Sentinel's health by almost a third, giving him around the same HP as Viewtiful Joe. This, combined with more people taking advantage of his massive size and very slow attack speed, has made him much more of a tolerable threat. The game's game breakers at the moment are now considered to be Phoenix and Wolverine (the latter arguably qualified as a game breaker in every other Marvel vs. Capcom game except MvC2). Phoenix is extremely fast, has an amazing teleport, has fire balls that home in on you and prevent almost any significant forward movement all at the cost of laughable health... until you do land that hit and make her transform into Dark Phoenix, where she gains even more power, chips life away very easily and boasts the same extreme mobility of her normal self. Wolverine is extremely fast, very powerful, has one of the most useful pressure moves in the game with his dive kick, can use his Berserker Slash for easy mix-ups and destruction of any zoning attempts, can use his Berserker Charge to make himself even faster, and can even create hyper combo loops with his Tornado Claw to kill characters from 100% life.
And then there's the DHC Glitch. When a character puts their opponent in a "grabbed" state, then cancels their Hyper Combo into one of their teammate's (referred to as a Delayed Hyper Combo or "DHC"), and that hyper utterly fails to hit the opponent, the damage scalingnote As you chain more hits together in a combo, each succesive hit does less damage. This is in place to prevent combos that easily kill every character, and is common in fighting games. and most of the hitstun scaling for the combo is reset. May sound difficult to do, but most characters have cinematic hypers, which count as a grabbed state, and can be cancelled into other hypers as normal. This means you can start a combo that ends in a cinematic hyper and does at least half of your opponents health, then cancel it into a teammate's hyper that doesn't hit (such as, say, a power-up hyper), then while the opponent is recoveringnote When you cancel a cinematic hyper, the opponent is launched a bit into the air for long enough for a hyper to fail and the one who used it to regain control of their character have that character do a combo to finish them off. Tournaments are basically first one hit loses that character. Thankfully this has been fixed in Ultimate Marvel vs. Capcom 3.
Ultimate, however, has brought in something Phoenix, Wolverine and the DHC glitch wish they had the power of. Meet Albert Wesker, who was already a very powerful character in the original MvC3. The character has a very fast teleport attack that gives him a fierce mix-up game, and he can cancel into this teleport off a shot from his gun. When a mix-up lands, his very high damage output will shave into your character's life bar very quickly. His normal attacks have gigantic hitboxes on them and are incredibly safe and easy to hit-confirm. He himself has slightly above average health, so it isn't that easy to kill him fast. He also has several counter moves at his disposal and has one of the best assists in the game in the aforementioned gun. What sets Wesker so far apart from the other powerful characters is that when his sunglasses come off (by taking damage... or, just landing his Phantom Dance hyper) he becomes faster and stronger than before, allowing him to easily kill characters from 100% life. He's very fast, very strong, difficult to defend against, difficult to keep out, difficult to kill, a very easy character to make huge comebacks with and outclasses a ridiculous amount of cast members (although not quite to the extent of the four gods... ish). Thankfully, tactics have been developed to counter Wesker's many shenanigans, though he's still considered high tier at worst.
Nearly half the cast has infinites thanks to a team aerial combo glitch that causes the game to not reset hitstun scaling, allowing characters that have at least decent aerial mobility to keep attacking the opponent until they get KO'd. However, this is less practical than it sounds, as the timing needed to be able to pull off these infinite combos is so tight that you'd need to be like a robot to actually pull this off in a tournament or online.
Wesker has been relieved (to an extent) of his Game Breaker status...only to be replaced by Morrigan. At first, she seems like a fairly average character, until you figure out her Soul Fist fly/unfly cancel. This tactic, combined with her Astral Vision super and Dr. Doom's Hidden Missiles assist, can fill the screen with projectiles and make it extremely difficult to advance towards her.
Currently occupying the top of the roost is Zero. Not only is he a small, fast and highly maneuverable target he can combo off almost anything he's got even at a distance, has brutal mix-ups, a powerful instant fireball and worst of all can 1 touch kill any member of the cast with 1 or 2 super meters (trivial since Zero builds meter fast) without X-Factor or even assists to extend the combo at times which is something almost no one else can do. Entire teams have been sliced appart by a good Zero player with Zero only needing to touch the opposing team once per character. Here's a demonstration of how nasty a combo from Zero is
Capcom vs. SNK 2 contained a glitch somewhat infamous in the tournament scene - by quickly cancelling a roll's opening frames of animation with a special move, the character was rendered invincible for most of the move. America's reaction was to ban it in tournaments, but it was not banned in Japan, leading to a rather sad display in the major international tournament when Japan walked all over America. Now, "roll cancelling" is generally required to play the arcade game competitively, although the glitch was fixed in the Xbox and Gamecube Updated Rereleases.
Cv S 2 EO solved the roll cancel glitch, but introduced a Game Breaker of its own — Easy Operation mode, or EO-ism (GC-ism on the GameCube). This move system was meant to allow novice players to play by assigning a special move to each direction on the right stick. Sounds fine at first, until you realize that this was done in such a way that it makes charge characters massively overwhelming. For example, a player using Blanka with EO-ism can have him continually do his forward roll attack, 6 times per second, without any charge penalties, and with little opportunity for the other player to respond, simply by holding the right stick in position.
The first Capcom vs. SNK had a ration system that totally broke some characters in the game. Nakoruru in particular is considered to be one of the most formidable characters in any fighting game ever.
From Tatsunoko vs. Capcom: Soki. Sure he doesn't seem cheap, but once he goes into his little transformation, he throws all of the rules out the window. He can heal, doesn't flinch unless he is hit by the strongest attack (one that takes 3 bars of energy to execute), and worst of all, his aura suggests that everything he is doing is fair.
His standing L is also another reason why people consider him to be cheap: it's a ridiculously quick sword poke with tons of range that can also cancel into itself and used to start his combos and thus any character without projectiles has great difficulty approaching him.
Also Tekkaman, considering his super moves are incredibly easy to accumulate, very powerful, can be done from a distance, and extremely hard to completely dodge, which means that even if they're blocked, the chip damage alone is sufficient.
Yatterman-1 has super attacks that automatically put him on this list considering how fast and powerful they are. His Yatterman Charge is so useful and powerful that it can take down the Final BossYami, in all three of his forms without even breaking a sweat.
By far the most formidable character in the original release of TvC, Cross Generation of Heroes, is Karas. His pressure game combined with his speed created nearly inescapable corner traps. If on defense, you had to do everything you could to get out of the corner when fighting him or it was a doomed game. Thankfully, his speed has been significantly reduced for the update Ultimate All Stars and thus has been brought down to a more reasonable level.
Gundam SEED Destiny: Alliance Vs. ZAFT II has two variants of the Strike Gundam banned from Tournament Play in Japan. The Strike Noir Gundam is a Lightning Bruiser with excellent offense and defense, good ranged attacks, nice melee options, and no real defects to speak of. The Launcher Strike Gundam is a Mighty Glacier ranged machine that possesses the ability to cover its landings, making it nigh-impossible to approach and counter.
In Gundam vs Gundam, the Strike's successor, the Freedom Gundam, is literally the god unit of the game. While its weapons list is fairly standard, its S.E.E.D. ability allows it to perform an instant dash-cancel, allowing a skilled player to rapidly set the distance of a battle as well as providing insane combo potential. As part of its rebalancing, the sequel gave this ability to every unit (under the name "Next Dash"), which only served to make the Turn A Gundam a Game Breaker in its own right.
In Gundam Extreme Vs., the 00-Qan[T] has fast melee moves and Attack Drones that can quickly knock down an opponent or form a shield that blocks everything, as well as a Super Mode that heals it upon activation and gives it a powerful full-map beam attack. To a lesser extent, the Susanoo thanks to its insane melee combos, Crossbone Gundam Full Cloth for being an all-around Lightning Bruiser, and Tallgeese III thanks to its heat rod being fast enough to punish just about any attempts at close combat. All of these received rebalancing in the sequel Full Boost, though for the Susanoo this entails shifting it up a tier.
Emerl's Ultimate skills in Sonic Battle. During the last part of the game, you can get these skills that are ridiculously powerful. However, thanks to the game's Skill Point system and each of the moves' high cost, you can't have them all on at once without the use of a Game Shark.
Emerl has a nasty glitch with his default Air Shot, which is supposed to be weak, as well as with Sonic's Air Shot and possibly Ultimate Air Shot. If performed low enough to the ground, the animation comes out but Emerl will land and cancel the move before the whole attack comes out. What makes this Gamebreaking is the fact that it still has a hitbox for those few frames, and if done at max meter, it doesn't use it up. Problem is special moves are instant kills at max meter and are supposed to use it up. The fact that it doesn't means Emerl suddenly has a one hit kill move he can keep permanently. Best part? Since the shot doesn't come out when he performs the glitch, it doesn't count as a Shot move, so you can't autoguard against it by setting Shot to defend.
The basic combo in the game ends with a Heavy Attack that dunks for a groundbounce. If a character is fast enough, they can maybe land one aerial hit afterward. But if you're Tails, you can land as much as you want. His aerial attack keeps him in the air, and bounces his opponent up. The opponent MIGHT eventually fall down, but they're always going to die before that happens.
Amy has the simplest one: Her literal Jab Lock. The hitstun on her jab is higher than the recovery, meaning with the right rhythm, instead of continuing the combo after the jab, you can keep on doing that first punch over and over again, and the opponent will not be able to break out. Repeat until death.
The AI is also not too smart. You can do all sorts of things to beat them really easily, such as:
Spamming Air Traps with some characters. They'll bounce up, and then land in the trap again, and never think to move out of the way.
Spam Rouge's Ground Power, especially if you're at the perfect distance from a wall that you can hit them again before they hit the ground. A human opponent would tech the wall. The Computer only ever does that in reaction to Heavy attacks, so they're stuck.
Extremely aggressive AI such as the final boss can easily be dealt with by Sonic. Spam ground power until dead. They set Power to defend? Spam Air Shot instead.
The opponent almost never blocks. You can easily keep them in a Knock Down loop if your character has a quick enough knockdown attack, such as Sonic. Even better, use that time in knockdown to heal a little before doing it again.
Tech Romancer has a basic game mechanic called the Iron Dash, where your Humongous Mecha rams the opponent. It does no damage, but leaves the victim open to a follow-up attack. This includes any Limit Break and even the mech's Final Attack. Once a player beats their opponent down enough to activate it, they're one Iron Dash away from victory.
BlazBlue has its resident Robot Girl, Nu-13. When played in melee (as in the 2009 Arcade Infinity finals) she's balanced (somewhat - the reach and priority on her C-attacks is far better than they should be). However an expert Nu player will use her knockback and teleport moves to avoid melee at all costs. Staying at range lets her play defensively, and abuse her absurd projectile combos. While BlazBlue's system does penalize excessive defensive play, Nu is allowed to stay defensive longer than any other character before being penalized. Longer even than Hakumen, who's meant to play a defensive/counterattack game.
Not to mention the infinite combo on Carl, is not subject to the combo rule on BlazBlue because it contains a throw, which means he's rather nasty in the hands of a skilled player. See here for a good example of the loop.
Ice Car must have been nerfed in Continuum Shift, because now all Jin does is spam his ice swords until he gets a health advantage and then run away waiting for the time to run out.
And of course, all the unlimited characters. Essentially, these are alternate forms of the characters that take their advantages and crank them straight Up to Eleven. For example, Ragna is in constant Blood Kain with a larger health bar (AND no life reduction), all of Jin's specials are the drive variant with no meter cost, Arakune can instantly curse you and his bees are almost the size of Carl, and Tager gains two spark bolts and a greater magnetism radius. But the real "fun" starts with Hazama, who has a perpetual green aura surrounding him. Should you touch this, you will lose health as long as you are in contact with it. And all of that health you lose? Yeah Hazama gains that much added to his own health meter. Oh, and guess what? Remember that short-ranged special that stuns the opponent? Well, now it automatically chains into the second part of his super autocombo. For no heat cost. And it's unblockable. If he gets too close to you, consider a quarter of your life bar gone.
Unlimited Taokaka, whose Drive attack can take OVER 50% OF YOUR LIFEBAR AWAY. AND YOU CAN SPAM IT AT NO COST!
Except against more seasoned veteran players. The longer charge time means it becomes easier to predict the moment of attack.
Someone discovered Noel's extremely useful single-move combo that can be kept up without a break. Her 2D drive; an overhead flip that fires the guns downward into the enemy, causing the target to get stunned for a moment - even the cancel/recovery takes long enough for the next attack - and can be continuously spammed once the player on the receiving side runs out of bursts. Of course, the first hit has to connect without being blocked or else it can be countered. But as soon as the first hit connects... You then realize you can continue doing it and keep on looping it until the opponent's life bar rests at zero. Never mind the gold and green bursts or blocking and barrier, mistime the blocks and you'll get owned. After the bursts are all gone... et tu, Brute?
Continuum Shift Extend gives you Platinum the Trinity. Platinum's projectiles are very very annoying if you cannot properly counter and predict her attacks... wait, it's both he and she. That cat face missile is huge. And by the time you recover from blocking or from being hit by the missile, she/he has another set of three ready to fire. You don't really need More Daka when those projectiles are about one-third the height of the entire stage.
Even BlazBlue: Chrono Phantasma is not safe. Say hello to Kokonoe, whose assorted setups, "touch of death" combos (many of which were discovered within the first day of her release as DLC), chip damage and overwhelming attacks have invoked deliberations towards banning her from competitive play until she gets balanced. This goes so far as to tracking down the PSNs of known Kokonoe mains to outright block or avoid at this time. Some have even gone so far as to put her in her own tier in 1.0 tier lists. Not since the days of #Reload Eddie has a character in an Arc System Works game been considered that far above and beyond the rest of the cast.
Even after being nerfed in the arcade patch (Version 1.1), Kokonoe is still considered to be one of the best characters in the game. The only difference is that now she has to share a spot with others.
In Dragon Ball Z: Budokai Tenkaichi 3 there is Tien, with his Neo Tri-Beam. The attack, which is his ultimate, is nigh-on impossible to dodge consistently without being lucky enough to fall behind an obstacle. Once it hits a target, that target is forced into its "falling down" state, and is unable to move until the attack is over. This wouldn't be a problem, if it weren't for the fact that this attack can be fired more than a dozen times in one activation, enough times to kill ANYONE who hasn't been enhanced for higher health. Suitably enhanced, Tien can fire this attack as his second action in battle (the first being charging to Max Power).
The main Game Breaker in the Tenkaichi series comes from the first game, as Krillin's Destructo Disk special. It's almost impossible to dodge at medium range, as it goes wide and then crosses you at a huge speed, and can go straight up! He was also one of the first characters you fight in story mode (as training for the actual fight against the Saiyans) so, needless to say, you got a crash course in dodging.
In Budokai Tenkaichi 2, one version of Vegeta could Beam Spam for just one energy bar. Even without charge-quickening upgrades, he was still deadly just by spamming it.
And then there's Great Saiyaman 2, a.k.a. Videl's powered-up form. She has an attack called Justice Countdown that, unlike every other rush-type Blast 2 in the game, has zero lag in execution, and to make matters worse extends the opponent's hitbox just far enough to make it completely impossible for them to intercept the move, or even block it. It can be dodged, but this requires god-like reflexes to the point where it seems only the AI opponents can ever pull it off, and it probably says something that even THEY usually don't. On top of that, the speed at which a fighter gathers energy is based on the fighter's raw power and is meant to balance the game; fighters like SSJ 3 Goku gather power agonizingly slowly, whereas Hercule has one of the fastest charges in the game. Because Great Saiyaman 2 is viewed by the game as a "weak" character, her charge is fast enough that she can spam Justice Countdown, as 2 energy bars are filled in less than a second. Making matters even worse is the fact that she has After Image Strike as a Blast 1, which allows her to dodge virtually any attack, even Beam Spam. And unlike the other characters with After Image Strike, she can do it for 2 energy bars, whereas everyone else requires 3 (and on longer charges).
Super Saiyan 2 Teen Gohan is one of the fastest characters in the game, hits like a truck, has great ki control, and has great stock moves along with one of the most powerful ultimate moves (Father-Son Kamehameha an unblockable cutscene attack) in the game that can be powered up using his stock move "Unforgivable" to do obscene amounts of damage to any opponent he faces.
Yajirobe, in all of his glory counts for this. He has good attacks that allow to fight up close or at a distance, great ki control, and the best thing about him is he has the fastest stock recovery of all the characters in the entire game! His Level 3 stock move is "Super Unyielding Spirit" which automatically gets him to MAX POWER and his level 5 stock move is "Senzu" where he eats a senzu bean and recovers all of his health. It gets even worse when you consider his ultimate move (Miracle Ka-Blam Slash) is one of the few rushes that can hit giant characters, and you realize that Yajirobe is practically the definition of this trope.
Nuova Shenron to an amazing degree considering the fact he's just a stronger and faster version of Pikkon who's already game breaking enough on his own. His Burst Attack projectile is very powerful and extremely spammable, his ki control is one of the highest in the game, and unlike Pikkon who has Burning Shoot, which is a rush that can be blocked, Nuova Shenron has Burning Tornado, which is a charge and can't be blocked, even by giants. Considering that his stock moves can be used to increase his already high attack and ki control, and you pretty much have a solid contender for high-tier characters.
Great Ape Baby Vegeta is a definite game breaker. He's a giant character, meaning he's resistant to knock back from most characters, cannot be thrown, is immune to most rush-type Blast 2/Ultimate Blast attacks, and has high attack/defense/blast stats. Unlike other large characters, however, he has low energy requirements for his beam attack, he can recharge his energy quickly, and he is very fast. This is so much worse when he's controlled by the computer.
If you're talking about Game Breakers, then you have to include Majin Vegeta, Legendary Super Saiyan Broly, and Kid Buu. Yes, these guys are supposed to be strong in the series, but these guys take it to the next level. While most Super Saiyans are somewhat balanced and make up for their impressive strength with slow to average ki recovery at best, these guys have some of the fastest ki recoveries in the game as well as crazy strength. They also have stock moves that can instantly make them reach MAX POWER, without becoming fatigued and having slower ki recovery than normal afterwards. As for Kid Buu, he has some of the best attack, speed, and ki recovery in the game, and has a stock move that can recover him back to full health. All three of these characters have special projectile moves that can take around a bar or more of damage, and their super moves are so powerful they can destroy the planet. Even if Majin Vegeta's Ultimate move causes some serious recoil damage, his basic move set is so effective you probably won't even need to resort to it.
Bardock is no slouch, either. In addition to having Wild Sense (which acts similarly to After Image Strike) as a Blast 1, he possesses two very powerful ranged specials that can deal over a single bar a health without needing to be charged. As long as the opponent has been sent flying first, these atacks will almost always hit.
Dragon Ball Z: Budokai has Android 19, who was effective for a beginning player, but absolutely terrifying in the hands of a skilled player, as his moves were very powerful, and his Ultimate move Life Drain 19, was incredibly easy to connect, did a high amount damage to the opponent, and recovered most of Android 19's health in the process. This was so bad that most people looked forward to fighting Perfect Cell over seeing Android 19 in battle.
Dragon Ball Z: Budokai 2 has Android 20, a.k.a. Dr. Gero who was everything Android 19 was in the previous game, except smaller and faster, and was actually more powerful than he was since his Ultimate move Life Drain 20 was even more effective than Android 19's was in that can be repeatedly used. This actually carried on into the next game where he was just as effective as ever.
Dragon Ball Z: Budokai 3 has several Game Breakers as well. The most obvious ones are the "revive" capsules, Frieza's/Cooler's Spaceship/Babidi's Mind Control. Essentially, they revive the fighter when dead to FULL health and Ki, in addition to making them far more powerful than they were to begin with (for instance, Majin Vegeta has an instant kill move). Less obvious is the "Broken Combo": Viral Heart Disease/Vaccine/Yakon/Gero's Deflect-back R&D .This combo automatically drains most of an opponent's health while making it INCREDIBLY difficult to fight transformed (i.e. as a Super Saiyan), all the while automatically sending Ki Blasts back at the opponent by blocking. Add this to Dr. Gero, who can absorb Ki Blasts anyway, and you have the formula for being quite.
Super Saiyan 4 Gogeta. His Ultimate Move, 100x Big Bang Kamehameha, takes off THREE life bars if you win the attack struggle. That's (usually) enough for a one-hit kill. Unfortunately for you though, you only get to use him once in the storyline, and Fusion Dance is Awesome, but Impractical in general. Still, he's powerful enough that in the one time you do fight as him in Dragon Universe (against Omega Shenron) you can basically do an Ultimate Move straight away and win. (And doing this nets you a Story Reenactment, too). Adding to the convenience of this character is the fact that you cannot fail the fusion (unlike the other fusion characters), though admittedly it's pretty easy to execute a fusion anyway.
Raging Blast has its moments, too - particularly Captain Ginyu in Team Battle. You can fight with him until his health is low, have him use Body Change to regain health, switch to another team member, switch to a THIRD team member (or have the second transform if the situation allows), and then switch back to Ginyu. He will be in his own body again, and thus be able to use Body Change again. Until the other fighters in your team are beaten, you can essentially make Ginyu immortal.
A great Game Breaker in Raging Blast 2 is equipping Guldo with Unexpected Blow and anything to increase Ultimate Attack damage. Charge him up to High Tension, activate Raging Soul, and you can use the Guldo Special up to four times in succession. Since the attack is unblockable, difficult to vanish from, and homes in on the victim, this is a huge game breaker to those who don't know about timed hits.
Goku himself is a game breaker in Raging Blast 2. It comes with the territory when your most powerful attack can only be accessed in the base form (and there is no energy struggle or combo necessary like in previous games). Goku also has a Kaioken finish, a high priority attack which guarantees an opponent's health bar without using too much of Goku's energy.
No love for Infinite World? Yes, the same gamebreaker of Budokai 3, Gogeta (both Super Saiyan 2 and 4 versions) and Vegito are there, as is Omega Shenron, but these guys pale in comparison to Baby Vegeta. How great is he? You know Vegeta's super moves, Final Flash (once only usable as a Dragon Rush ender in 3) and Big Bang Attack? Baby Vegeta can keep using those as regular moves! Even GT Vegeta only had the former! On top of that, he has a super on par with other fighter's super moves. The only characters that really stand a chance against him are Super 17 and Janemba, and even then, you have to get lucky.
The characters are fairly well-balanced with the exception of Louis. At first appearing to be the Mighty Glacier, Louis is the slowest character, but does above-can use his armor to block a hit and counter with a strong grab: good, but not excessively so. Then, you find out that he can transform into Louis EX when he's on less than 25% health. This causes him to lose the armor, but it vastly increases his speed, and he gains a spear that gives him the best reach in the game and can spam instant-hit ranged attacks that knock back multiple targets. Hopefully, you can finish him off by attacking him just as he finishes his uninterruptible transform which also deals damage.
Rudolf has an Invisibility and Multiply techniques, which turns Rudolf invisible (and invincible) briefly and summons a couple of copies of himself with the same capabilities but laughable health respectively. The gamebreaker comes when Rudolf finds a beer bottle to recover mana, allowing him to spam clones almost endlessly and then make all of them invisible. With enough clones, they end up being incredibly sturdy and may even turn invisible or multiple themselves! Luckily, there was often a pact among friends to simply abstain from using him altogether.
If you just type in "lf2.net" when the game is loading, all of the characters will be unlocked, including the final boss Julian. He has a three-burst homing attack, an energy ball attack that plows through dozens of enemies and is unblockable, and an explosion centered on himself that sends enemies sky high while dealing incredible damage. The best part? Each of these special attacks cost so little energy that spamming them is incredibly easy. Oh, and his normal punches do about as much damage as the sword blows of one of the other main characters. One can easily wipe the floor with the above Louis EX with Julian.
One of the first alternate versions, R-LF 2, is practically MADE of this trope. See, every character in the game (yes, even those Mooks you could kill with ease) are given new attacks, and have their old combos re-vamped. For example, remember that crappy fire-breath move Firen had? Well, now instead of occupying 2-3 spaces it stretches about 2/3 of the whole screen. Not game breaking enough for you? Ok, how about the fact that every character also has a hidden "Hell" move, that pretty much ends the fight once you use it? "Hidden" it requires a unique multi-key combo to pull off, and under a set amount of time as well. Although this sounds like it evens things out, some of said combos are so ridiculously easy to pull off it's almost laughable. Case-in-point: those purple explosions Julian's Soul Bomb causes when they hit something? Well, Julian's Hell move consists of just that one explosion. That multiplies. As a whole wave of explosions. That start from his position and move both ways, enveloping the entire screen. Now imagine your character caught in that maelstrom of explosions. Yeah.
AND if you thought that the Final BossJulian in Reinforced LF 2 was cheap enough, then you haven't seen the secret character Conrad yet. Remember those deadly columns that Julian could create? This guy creates an entire wave of them, on BOTH SIDES. He also has many other moves, especially the Hell Moves- one of which summons a purple dragon that charges the crap out of enemies multiple times, another makes him delete one victim from the game (works on the FinalBoss, by the way), and another makes him trap enemies with homing columns of dark energy until they die... after which said columns do not disappear, instead moving on to seek out more enemies and repeat the process. As for defensive abilities, Conrad regenerates health faster than anybody else (over 10x the normal speed), and to top it all off, he gets Mercy Invincibility every time he gets hit. In short, Conrad makes Julian look like a complete joke, and that's saying something.
Firzen in a particular version of little fighters (Little Fighter 2 Kate version...) has a move that requires a small bit of his health and mana and sends all enemies on the side he is facing into the skies burning and freezing as though they hit an invisible wall of fire and ice. As if that weren't enough, another key click and he cuts them in the air with invisible blades all off-screen, sending their burning/freezing (mostly likely dead or nearly dead) bodies flying from off-screen away from Firzen. Also, Arctic Volcano in the regular version already nearly insta-kills anyone near him. In Kate version, you can continue this until your run out of mana... or you can add the F6 key (infinite mana) and continue until everything is dead.
Kate from this particular series (looking like a person wearing a Pikachu suit) was made to blast everything in the way of the attack into oblivion with its multi-hit arcing thunderbolt attack, which is one of the regular special moves it has, and which has a huge range and the tendency to drag the target along with it.
Firce777 is probably the most effective mod character. He shoots a wave of fireballs and wave of iceballs in front of and behind him, respectively, while standing. He shoots a wave of arrows, explodes and spawns tornadoes when walking. He can also spawn five Firzens as well as five energy discs and increase his mana by a little bit (the creator names this move "Five Loaves Two Fish"). And for the worst part? He can turn invisible for free and cause his Firzens to turn invisible as well.
Eternal Fighter Zero features two SNK Bosses, but only one was de-powered for the playable version. The other, Kanna, retains all of her insane range and priority attacks, and is thus usually banned from tournament play.
In Custom Robo for the Gamecube most if not all the illegal parts fall under this trope. The most egregious is Rahu III and his associated parts. He is the only robo who is immune to the fallen state, where a robo drops to the ground and is unable to do anything and the enemy can pound away at it. The Rahu III body takes only 20% of normal damage from all attacks. To top it off, all of his weapons are extremely powerful and have an enormous blast radius.
The X laser illegal gun to a lesser extent when you use it right. Technically it is noted to have a weakness when you fire it at point blank range but that only applies IF the opponent is already within your attack radius with a faster gun (few are faster). The X laser can not just fire around obstacles but it has a high downing rate so it takes about 1 or 2 shots to down your opponent. A skilled user can just sit in one place and pluck your opponent down at his or her leisure.
Another is the Wyrm illegal gun. Thought Dragon was powerful? This gun lets you fire FOUR OF THEM AT ONCE. From the air it also alleviates the Wyrm's single weakness by firing a single high speed shot at the same face value.
Another self-discovered combo is the Athena Raptor gun illegal combo. Normally when you fight the Athena models, you are fighting them with a waxing arc or a waning arc (left- or right-curving guns). Now, although those guns are awesome, they don't actually play to Athena's strengths. Athena has 6 additional jumps. With the right timing, one can reach the top of the screen EASILY with Athena. That is where the Raptor gun comes in. When you are in the air, the Raptor will fire a standby round that stays in place. The number of rounds you can keep up at once is about 10 at a time because at that point they start firing and you shoot at the rate they start dropping. Though this doesn't make it too effective, it is the fact that you are effectively slowly dropping as you fire this gun. By the time you reach the ground, your opponent will be full of holes and by the time they raise their gun to shoot at you, you'll be back in the air already.
Can be extended further with a Lightning sky model, the MOBILE extension to this trick. Now you can fire like crazy while not being a stationary target.
The Crystal Strike illegal gun. Just mashing the fire button can send an unending stream of death at your opponents, and if just one hits, they ALL hit.
Stun Gun + Formula Legs + Peregrine body (a Fragile Speedster) = a robo that can pin an enemy and stun the everloving crap out of them. Several hundred hitpoints can be removed by one of these robos in under a minute. What's more, using a fast enough Robo (of which there are several), it's even possible to—with a fast enough reaction time or reading ability—run around incoming projectiles point blank like the Flash, basically neutering the opponent's ability to stop your advance unless they use a weapon with a large enough spread.
If you think any of that was bad, try using the knuckle gun on one of those robos in exchange for the stun gun. The knuckle gun is exceptionally hard to use, but if you manage to learn it, it would be quite easy to take out over 400 hp in a matter of seconds.
In the Naruto Ultimate Ninja series, there is a game breaking trick in which if you charge up your super move while an opponent plane shifts toward you and you're the proper distance from them, you can time the initialization of your super move just as they come down. Since you're briefly helpless during this, if your opponent does this trick, they get a free hit. This trick is difficult to counter if done correctly.
The speeding dash into your guard, that leaves them open to a special jutsu. Hurray for AI lag. Oh, and Tenten and Kurenai are insanely formidable. Tenten can fling anything out and has some heavy items and an array of dakka enough to bring even Sakuya to shame. Kurenai, however, has some attacks that make her disappear, keep her opponent at range while she stays stationary, has a bomb attack that just EXPLOES in your face, and some drill lock speed combos. Also of note is Ino, who has insane drill lock combinations and speed. She can also poison you, and places herself in some positions where it'll be a miracle to hit her.
The ultimate game breaker in the PS2 games in this series is button locking. Performing a quick dash, knocking your opponent up into the air, and then throwing kunai at your opponent causes the opponent to not be able to register any button presses, leaving them vulnerable to level 3 specials.
Naruto Shippuden: Ultimate Ninja Storm 2 gives us Deidara, who can kill you from across the screen without leting you get close by spamming his laser guided bombs, which can stop your chakra dashes or attacks, and using chakra back dash to keep out of reach.
Also in the Ultimate Ninja Storm series, the Left Stick Flick attacks. Most people don't know how to do them because of the bad instructions on the control menu, but once one figures out how to do them, they break any fight. In the first Ultimate Ninja Storm, as well as Generations and Ultimate Ninja Storm 3, Part 1 Naruto's is particularly infuriating, as it covers a large distance, can be spammed endlessly (due to the attack type not using any chakra), and the user can then run while the clones keep the enemy at bay. On top of that, it also cuts chakra dashes, launches insanely quickly, and does relatively decent damage.
There is a gamebreaker using the Shadow robot. If you stun your opponent, grab them with a shadow double and perform a combo on them, the enemy will only get up stunned again, allowing you to repeat this ad infinitum. Effectively, so long as you can stun your opponent once and perform this trick, you win.
A similar trick can be performed with the Chronos robot if you freeze your opponent in the air, combo them, and freeze them again, rendering them absolutely helpless. Even the CPU on Ultimate difficulty can be taken down easily using this method. The Chronos has a combo that involves using its time freeze projectile, attacking the opponent while they're frozen, and knocking them into the air, so you can time freeze them again and knock them in the air while they are helpless. If timed right, this combo is pretty much unstoppable and makes even the Ultimate Mode seem like a joke.
The Gargoyle mech has a nigh-unblockable aerial throw and decently powerful attacks, and a shoryuken with the most ridiculous invincibility frames ever. To make matters worse, it can chain the air throw out of the shoryuken. Oh, and everyone online plays on Hyper Mode, which makes the game moreStreet Fighter, giving rise to the impossibly powerful "Triangle Jump" technique. Ironically, Gargoyle's countpick is Jaguar, which is still fairly decent (it's the starting mech in tournament mode).
See also the Katana. Not gamebreaking unless it's playing with all upgrades—in which case it has the stupidly powerful Fireball projectile and a five-hit Shadow Rising Blade rush which it is completely invincible for the duration of.
There is also the Shredder, who is above-average at best until you click over to Hyper Mode. As game guru Robyrt put it, "If you land a flipkick or headbutt with Shredder, your opponent should die."
Also, some of the possible combos (Robyrt has some cool ones on his site) are flatly ridiculous. Against a suitably slow opponent with a suitably fast pilot, Jaguar can chain two Overhead Throws (air throws that hurl the opponent across the screen, in a game without dashing) together. And the Nova can use its aerial bellyflop, which knocks down an opponent, and chain it into the grenade...then hit the opponent as they get up, knocking them back into the grenade. Similarly to Jaguar, it's possible for Flail to chain its Spinning Throw into itself, but that is even MORE ludicrous, as it sends them flying almost on the ground.
Using Steffan or Jean-Paul as your pilot will make matches much easier considering their nicely balanced stats, and their ability to function with most of the robots pretty well overall.
Gargoyle is technically the best robot, but it requires you to have consistent execution. Electra, on the other hand, has stupidly good punch attacks, one of which can lead to an infinite if your pilot is fast enough.
The Star Wars: Episode 3 game has Serra Keto, Cin Drallig's apprentice who uses two lightsabers. She is SUPPOSED to be a defensive character, and therefore has the best run speed. However, her attack animation is quick, and consists of hitting the enemy on the head, causing some stun... and letting you follow up. Only, that attack causes stun too. So you can keep attacking, and keep spamming, easily outclassing even the offense specialist. Except if they try to break off, you can just chase after them and start spamming again. Her attack power is only a little bit below average, but it's INSANELY easy to make both hits connect, and to start a flood of hits, letting you take out a good portion of the opponent's health very quickly. Its possible with good timing you might even be able to make an infinite combo.
In the WWE Smackdown vs Raw series, as the games evolved and improved things like blocking and countering mechanics and collision detection, some moves that had been present in the first game were never updated, and still played the old sloppy way. When Smackdown: Shut Your Mouth introduced online play to the series, players discovered that a lot of the older moves couldn't be blocked. The "women's toe kick" and "diving headbutt" being two of the most notable and abused. While most players refrained from using them, some went the other way and sought out every single glitchy or unblockable move and called anyone who complained about this a scrub.
Tangentially related to the above: in the old, old, old WWE game WWF WrestleMania Challenge for the NES there was Andre the Giant. Andre was fine enough to face with the computer controlling him in "Championship Mode", but when playing two player versus, one of Andre's moves was the bear hug, executed simply with the B button, the bear hug had no maximum time it could be applied, it was uncounterable, and there was no way to escape it. The player playing Andre could slap it on, hold it until the other player's stamina was depleted, then pin the guy. Oddly enough, the computer wasn't cheap enough to employ this tactic, even thought Championship Mode's Ultimate Warrior was an SNK Boss.
Of course Andre also had a big weakness: he was not programmed to enter or exit the ring like everyone else or climb turnbuckles. If you can knock/throw him out, it's instant count out victory for you. The Ultimate Warrior's gorilla press slam was excellent in this regard.
WWF Attitude had the Crucifix running pin move. If the opponent's health bar is down to yellow, which is easily achievable, it's an instant win. Most Pin moves are only effective when the opponent's bar is red.
The main reason why the omniblock does not work on those attacks is generally because that attack either strikes from directly above or below (where Omniblock does not guard against), has a disjointed hitbox (bypassing the guard altogether) or with a discrepency in the execution (where it can be blocked but not reliably). That said, they are not so much as counters as they are attacks that just happen to have strange properties. Examples include Zidane's Free energy which activates VERY FAST and hits at the target's exact location and Cloud of Darkness' Aura ball which does not count as HP damage until they explode and you can sneak one past the shield without triggering it(although gauging the distance is the problem).
In a more benign direction, there are circumstances which, if stacked properly, let you zip to Level 100 in one fight. It's generally called the "Exdeath cheat"ónot because it depends on him, but because his particular flavor of Artificial Stupidity is the easiest to work with while you're setting up the in-battle conditions that make it work.
Exdeath is...well, he's still as amazingly powerful as even in Duodecim, but a new addition may have dethroned him from the title of Resident Game Breaker—you see, Exdeath is still allowed (indeed, almost expected) in tournaments. [Via Dolorosa—er, Feral Chaos, is not.
Battle CAPacity formerly had Pyroak as absurdly difficult to fight, thanks to incredibly effective projectiles, a grab which knocks the opponent away if they approach, the best anti-air move in the game hands-down, and Wood Hammer. Wood Hammer is an overhead attack which comes out absurdly fast, shuts down reckless offenses, and screws over turtlers which can't shift to a high block in time. He's been nerfed to a degree, and while he has the best matchup against one of the other Game Breakers, he isn't absurd.
Speaking of the other Game Breaker, Revenankh. Rev has the best wake-up game in Battle CAPacity by a wide margin, with a wide variety of powerful grabs, including an air grab, an anti-cornering attack, and one of the other best anti-air attacks in the game. He also has very safe approaches thanks to Shadow Punch and Bind, and can combo Shadow Punch into his close strong, followed by said anti-air, then his air grab (25A/B, c.5C, 4B, j.G). He gets mightily screwed over by Pyroak, however, thanks to his projectile trap. Like Pyroak, he's also been nerfed, but is still considered one of the best characters.
The current contender for Game Breaker staus is Skulloton, whose boomeranging projectiles, launcher combo, and excellent comboing abilities allow him to tear huge chunks of the opponent's life bar off very quickly.
The lesser-known fighter Battle Blaze on the Super NES featured a quick AI that was able to tear you apart in seconds if you let it. That is, until you discover the magic of the relatively simple "Forward+Y" move. While essentially a throw, all characters are quick enough to run over to an opponent and grab them the moment they are standing upright again! During "The Hero"/story mode, you can keep throwing the computer opponents the moment they get up with very little retribution, if any. This "throw" even trumps any attacks they might use, allowing you to gain perfects on opponents up to and including the final boss with only minimal effort!
Older Than The Nes: The Way Of The Exploding Fist. Since the game uses shobu nihon kumite scoring, the priority is knocking the opponent over rather than wearing down their energy bar. In real karate, the leg sweep is perfect for this. In Fist, the leg sweep is a little too perfect; the first ten levels can be completed with nothing but the leg sweep.
Elsa in Arcana Heart 3 has several infinite combos, depending on which arcana is selected.
Touhou's Immaterial and Missing Power spin off grants us Patchouli Knowledge, probably the easiest character to win the game with due to how in-game bosses react to one of her attacks. Sun Sign "Royal Flare", one of her second signs in the game, hits all around the screen for an obscene amount of damage. Due to the way Spell Cards are declared, you can build up 9 cards on your first life and then spam Royal Flare on your second; note here that you have to die twice in order to lose a life (they have to beat both of your spell cards), so losing once per fight is practically meaningless. Even if the enemy survives those 9 Royal Flares, the Spell Card System allows you to farm for more in the same life. Player spell cards cannot be canceled once initiated, leaving the opponent with the little time between cards to counter. Even if bosses could block during their spell cards, both grazing and blocking have a finite duration, so they would eventually fall prey on Royal Flare due to guard breaking or them just plain stop grazing out the damage. Patchouli still has Royal Flare as her spell card on subsequent fighting spin-offs for the same effect, but the new system restricts it to a maximum of 4 declarations, once per card equipped, at the highest casting cost.
Sonic the Fighters has Sonic's spin-dash move. Even on the hardest difficulty, this move will mow down any of your foes like a hot knife through butter, due to its excellent damage and the recovery time it has your enemies go through, with the possible exception of Metal Sonic. Even if you block it, a direct hit will STRIP OFF THREE BARRIERS! The default number of barriers you have is three and you can have a maximum of ten depending on the settings and almost all the other barrier breaking moves only break one of them. If you let Sonic (Or Tails, Knuckles or Espio) hit with a Spindash twice, then you're pretty much defenseless for the rest of the match.
Ickybod Clay and Taffy in the original Clayfighter, due to their incredibly long reach.
Gage Novus in the original Forsaken Chronicle due to the sheer speed and damage output of his moves and the infamous Hell Step which involves a lightning fast, heavily damaging, stomp that stuns your opponent on the first strike, knock them to the ground on the second and can hit them on the ground anyway. Four of those can kill Unit Alpha and Connor Omega (Who have the highest HP other than Gage Novus).
Injustice: Gods Among Us, prior to the 1.05 patch, had Scorpion. Besides that fact that he was already hated for being a Guest Fighter in a game of exclusively DC characters, he retained his Mortal Kombat 9 moveset. The problem? Injustice lacks a block button like Mortal Kombat 9. The Teleport Kick was basically the most powerful move in the game, even more so when he meter burned it for a followup combo, and it was even safe on block. Even though his damage was(and still is) the lowest of the cast, his amazing moves made up for that. Thankfully, he was toned down for the next update.
However, the true Game Breaker in the eyes of many is, as of current, Superman. Why? To start off, he was powerful from the very beginning, but his prowess was overshadowed by characters such as Deathstroke, due to the latter's seemingly overpowering zoning (which has always had counters). After Deathstroke was nerfed, Superman's true power came to fruition. His zoning is EVEN MORE POWERFUL than Deathstroke's, to start off, with the 3 variants of the eye lasers. As such, it's not uncommon to find Superman players online who win by standing in the corner and firing these lasers until the opponent dies. But that's just the tip of the iceberg. Superman's combos, despite numerous nerfs to his strength, can do over 60% damage prior to the Complete Edition patch, with as little as TWO bars burned. Superman then went on to win EVO 2013 under the player KDZ, where it was shown that a Superman can be BRUTAL under a skilled player. To add to the Superman hate, audible boos were heard in the audience when he started to spam the lasers and win. From here, Superman was heavily taken down in the Complete Edition patch, which added more recovery to his lasers and nerfed his most used combo starter f+2,3 along with the freeze breath which was used to safely cause chip damage after a normally unsafe f+2,3 on block. Even after these massive nerfs, Superman is still considered a mid-tier character (at worst).
King Crimson, Diavolo's stand, as expected is a game breaker in Jojos Bizarre Adventure All Star Battle. He can cancel the priority of your moves and attacks even while you're comboing him, resulting in you doing nothing to him and him negating the damage you did.
Not only can he counter projectiles, the beginning of his dash lets him avoid them altogether, allowing him to close the gap quite easily.
Kat is universally considered the best character in the game. Completely safe jabs, many ways to kill an opponent just by touching them, a fantastic projectile in her debris, and overall great Supers with many ways to combo into them. She's the only character with an air dash as well. This allows amazing mobility, turning her into a Lightning Bruiser that is extremely hard to kill.
Raiden is known for his extremely long combos and reset opportunities, but what truly seals it it his very easy flip kick confirm(Launcher, Flip Kick, Level 1 Super). This technique is so hard to counter because it has many ways to reset and combo into it, and to top it off Raiden has fast mobility as well, making a single touch able to kill you if he manages to follow it up. Oh, and his counter crumples. Free Super.
Sackboy was the original game breaker for the fact that he accumulated energy necessary to perform special techniques way faster than anyone else in the game, especially if you used his throw. This was so bad that Sony got so many complaints about this that they instantly put a patch on him which nerfed this effect somewhat. Even after this nerf, his energy accumulation is still fairly decent and his specials are still pretty spammable putting him in mid-tier at the very least.
Kratos, ignoring Reboot Dante's crazily long combos and execution, has the most versatility in combos of the 3 combo oriented characters(Kratos, Raiden and Dante), mainly due to the fact that his Square moves(sans the grapple) are safe, have long range, and cancel into each other(sans grapple), and generally allow for easy bursts.Add that to the fact that he has great mobility, bar none the best counter in the game(gains 20 AP and has 2 variants: a crumpling projectile and a launching melee counter, for, you guessed it, projectiles and melee attacks), and many, many ways to cancel, Kratos is either this or a Lightning Bruiser.
Last in the most complained list is Isaac Clarke. Access to a variant of Drake's infamous Gun Loop is bad enough, but combine it with a useful throw that confirms into Level 2 and 1(through a glitch with his Force Gun) that also has reflecting properties(which can glitch and leave a projectile floating as a shield), plus many loops that can lead into kill confirms or that are TOD's(touch of death; one hit can lead into a life removing combo), AND a Level 3 that can end most 1v1 matches on 3 lives instantly and to top that is a '''literal'''Game Breaker, and Isaac earns that status.
Dragonball Xenoverse: Players discovered that bosses would randomly generate the equivalent of super armor and any attack during that time was nerfed down to nothing. But in the process of finding ways to counter that, they discovered two things: that grapple/throw attacks do full damage (equivalent to standard attack damage) every time and they had absurd priority. This rendered most boss fights (most fights period, if one felt like it) into "Grapple, Dodge/Defend, rinse, repeat."