Sephiroth

Sephiroth is the antagonist from Square Enix's Final Fantasy VII. He is a former renowed member of an elite fighting force called SOLDIER, who defected and went on a murderous rampage after discovering the circumstances of his existence. Sephiroth would then go on to become a world-ending threat for Cloud Strife and his allies to stop. He appears in Super Smash Bros. Ultimate as a downloadable character. Despite having almost all of his home series appearances dubbed in English, and a few earlier appearances dubbed in additional languages, Sephiroth, like his rival Cloud, speaks only Japanese in Super Smash Bros. Ultimate, similar to Marth and Roy prior to the game; he is voiced by Toshiyuki Morikawa, his Japanese voice actor from Final Fantasy VII: Advent Children onward.

Super Smash Bros. Ultimate
Sephiroth was released in Super Smash Bros. Ultimate as the third fighter of Fighters Pass Vol. 2, following Min Min and Steve. During held on December 10, 2020, he was announced as the fighter for Challenger Pack 8. A follow-up broadcast hosted by Masahiro Sakurai on December 17, 2020, further showcased his moves as well as his home stage, the Northern Cave. The pack released officially on December 22, 2020, though from December 17 until its release, if the player purchased the individual pack or Fighters Pass Vol. 2 and updated the game to version 10.0.0, they could partake in a "Sephiroth Challenge" event, where they could fight Sephiroth in a Stamina battle on the Northern Cave stage on Easy, Normal, or Very Hard difficulty. If the player defeated Sephiroth on any difficulty, they would unlock him, the stage, and its music early.

The reveal trailer for Sephiroth takes place during the events of the adventure game mode, World of Light, emerging during a fight between various characters and Galeem and several Master Hands. Unlike all of the other characters in-game, he is the only playable character that seems to not join forces with the cast; however, he cuts Galeem in half right before his appearance, seemingly being against both separate parties. Cloud then recognizes Sephiroth upon his appearance. After brief gameplay footage, Sephiroth is seen attempting to stab through Mario (a reference to his actions towards Cloud during the Nibelheim Incident flashback in the original game as well as a similar action in their duel in ), which is then interrupted by Cloud, and the two begin swordfighting.

Sephiroth is considerably lighter than previous DLC fighters; he is lighter than Meta Knight and Zero Suit Samus but heavier than Sheik, while having the same weight as Kirby, Pikachu, Mewtwo, and Olimar.

Classic Mode route
All of Sephiroth's opponents are bosses, making his Classic Mode route similar to Boss Battles mode from Super Smash Bros. Brawl.

Supernova
Supernova is Sephiroth's Final Smash. When the move is activated, Sephiroth swipes his Masamune in a wide arc. If at least one opponent is hit, a cutscene is initiated. Sephiroth turns into his final form, Safer∙Sephiroth, and begins an attack resembling his Supernova ability in Final Fantasy VII, summoning Meteor to wipe out several planets.

Trivia

 * Prior to formally debuting as a fighter in Ultimate, Sephiroth was frequently alluded to.
 * In Cloud's debut trailer for Super Smash Bros. for the 3DS and Wii U, Cloud faces off against Ike with the choreography matching up with Cloud and Sephiroth's metaphysical battle in the ending of Final Fantasy VII.
 * Cloud's All-Star Mode ending has him glaring at Palutena as she's walking through a blaze, alluding to Sephiroth and his role in the Nibelheim Incident in the game's backstory.
 * One of the unlockable images for Cloud in Ultimate has Cloud cradling Zelda while wading through a body of water, indirectly referencing Sephiroth's murder of Aerith in Final Fantasy VII and the funeral afterward.
 * Mewtwo's Classic Mode route has his "ally" in the third match being Cloud Strife, after beating him in the prior match, referencing Sephiroth's manipulations of Cloud throughout the game, and to a lesser extent Cloud's status as a Sephiroth Clone.