Meta Knight is a mysterious character who is seen as both a hero and a villain, and more generally an anti-hero, in the Kirby series. He is sometimes cast as an antagonist to Kirby, but his intentions are not generally portrayed as evil. In certain instances, he sends his troops, the Meta-Knights, as enemies against the pink protagonist as a sort of training. Titles such as Kirby & the Amazing Mirror, Return to Dream Land, and Planet Robobot depict Meta Knight as a direct ally to Kirby, often assisting him in his journey.
Meta Knight is a blue Kirby-like being cloaked in armor, with glowing yellow eyes visible underneath a silver mask. His primary weapon is a golden, pronged sword named Galaxia. He wears a cape that can turn into bat-like wings, which he uses to take flight. On certain occasions, he will throw off his cape, revealing his wings underneath. Meta Knight's mask breaks almost every time he is defeated, revealing a face very similar to Kirby's. Upon defeat, Meta Knight immediately wraps himself within his cape and flees.
In battle, Meta Knight has a notable code of honor. He always provides a sword to Kirby in order to have an equal duel; in some games, such as Kirby Super Star and Kirby Star Allies, there may be certain circumstances that cause him to make the first move when Kirby takes too long to get the weapon. However, in contrast to his code of honor, Meta Knight is also occasionally shown to be forceful and arrogant. This is best demonstrated in the "Revenge of Meta Knight" mode of Kirby Super Star, where Meta Knight attempts to use his battleship, the Halberd, to take control of Dream Land and end its carefree lifestyle.
The Kirby: Right Back at Ya! anime depicts Meta Knight as an ostensible underling to King Dedede; in reality, he has his own higher motives, and only uses his relationship with Dedede as a means of accomplishing them. He often acts as a mentor to Kirby, providing cryptic advice and training him to become a Star Warrior. This appearance is the basis of Meta Knight's personality in Smash. In Japanese, he is even voiced by the same actor, Atsushi Kisa'ichi.
Meta Knight only appears in this game as a collectible trophy, unlocked as one of the 250+ trophies that can be collected randomly during normal play, such as in the Trophy Lottery and throughout the various Single-player Regular Matches (though it will only be available to start appearing after the player has played over 200 VS mode matches). The trophy has a factual error: while his first appearance was in Kirby's Adventure released in May of 1993, the trophy claims that his first appearance was in Kirby Super Star, released in September of 1996.
The mysterious head of the Meta-Knights, he wields his sword with dignity. He delivered his sword to Kirby and demanded single combat in show of his knightly honor; his strict adherence to his code of ethics makes him a rarity in Dream Land. Sometimes he throws off his cape in battle. It occasionally transforms into wings.
As a playable character
Main article: Meta Knight (SSBB)
Meta Knight is a newcomer in Super Smash Bros. Brawl, and he is available to play from the start. Almost all of his attacks involve his sword, Galaxia, and most of these attacks are extremely fast; for instance, his up air comes out in just two frames (2/60 of a second), referencing his swordsmanship in the Kirby franchise. Though his overall reach is average, the length of his sword relative to his small body gives him grossly disproportionate disjoints in all of his attacks, giving him excellent spacing options. In addition to fast attacks, Meta Knight is equipped with incredible recovery potential. Like Kirby, King Dedede, Jigglypuff, he has multiple jumps, but, despite physically resembling Kirby, he doesn't puff himself up to fly. Instead, he transforms his cape into wings to propel himself upwards, and in addition, Meta Knight has the ability to glide using his cape wings. Furthermore, Meta Knight is equipped with very versatile special moves that not only improve his already stellar recovery but also heavily define his neutral and edgeguard game.
Meta Knight is widely considered to be the best character in Brawl due to his lack of disadvantageous match-ups (with one documented but heavily disputed even matchup against Pikachu) along with his overwhelming dominance in tournaments. Due to being considered "broken", Meta Knight had been banned since January 9, 2012 on the Unity Ruleset and has been the only character in the Smash series to be banned in standard tournaments. However, after the disbandment of the Unity ruleset, prohibiting him is up to the Tournament Organizer.
The head of the Meta-Knights, and something of a rival to Kirby. He's quite an accomplished swordsman. Following his code of knightly ethics, he once delivered his sword to Kirby and demanded single combat. His giant cape transforms into wings, giving him the power of flight. He's shown his face briefly before, but his relationship to Kirby is still a mystery.
As a playable character
Main article: Meta Knight (SSB4)
Meta Knight was confirmed as a playable character on August 13th, 2014. He has been visually updated, with his gloves now sporting gauntlets, a detail seen in official artwork of Meta Knight in Kirby: Squeak Squad and Kirby Super Star Ultra.
Possibly due to his dominance in Brawl, Meta Knight has been significantly nerfed from Brawl to SSB4. Many of his attacks are slightly slower, and his range has been noticeably shortened, forcing him to take a more aggressive play style. His attacks no longer have transcendent priority. He has lost the ability to glide, toning down his recovery. Mach Tornado, a staple in Brawl, has less momentum and higher ending lag, removing his dominance in the neutral game. These changes have also left him more vulnerable to camping strategies.
Meta Knight is currently ranked 16th on the tier list, placing him in the B tier. Meta Knight still has numerous strengths, such as his combos from Brawl, and his deadly edge-guarding game. He has received several buffs to his KO moves as well, with his forward smash and back aerial now dealing more knockback, and Shuttle Loop deals more damage, has increased range and much higher knockback scaling. As a result, he has a powerful punishing ability. Most importantly, his air speed has been greatly increased, now being roughly average, whereas it was tied for the third slowest in Brawl. Even with the loss of many of his advantages, his strengths heavily outweigh his flaws; this has translated to his tournament status, in which he has secured strong representation and noteworthy results.
As a costume
Meta Knight's mask is also available as headgear for all Mii Fighter types.
As a playable character
Main article: Meta Knight (SSBU)
Meta Knight returns as a playable fighter, as with all previous characters, in Super Smash Bros. Ultimate, now as an unlockable character. Although Meta Knight has received a mix of buffs and nerfs in the transition to Ultimate, but has been nerfed overall, although significantly less so than in his transition from Brawl to Smash 4. He also received a new Final Smash in the form of Darkness Illusion.
As a costume
Meta Knight's mask is once again available as headgear for Mii Fighters.