Pyra

Pyra is one of the main characters from Xenoblade Chronicles 2. She is a Blade, which are personifications of weapons used by Drivers in the world of Alrest, more specifically an Aegis (or Legendary Blade) that can be wielded by the game's main protagonist, Rex. She was created by Mythra as a different personality of her. Pyra uses a variety of flame-based powers in combat, whereas Mythra uses light-based powers. Both her and Mythra were released as a singular 2-in-1 downloadable fighter for Super Smash Bros. Ultimate.

Super Smash Bros. Ultimate
On February 17, 2021, during a Nintendo Direct, both Pyra and Mythra were announced as the fighters for Challenger Pack 9 for the Fighters Pass Vol. 2 in Super Smash Bros. Ultimate. They released on March 4th, 2021. Their reveal trailer features Rex (the protagonist from Xenoblade Chronicles 2) searching for Pyra, only to find her excitedly announce that she received a Super Smash Bros. invitation letter. Rex then laments that he thought he was going to be a fighter. A follow-up presentation showcasing Pyra and Mythra's moves in-depth and announcing their official release date occurred on March 4th, 2021.

Pyra and Mythra function as one character, with players having the option to switch back and forth between them, similarly to how Zelda and Sheik functioned in Super Smash Bros. Melee and Super Smash Bros. Brawl. Pyra's moves include Smash Flare, a very powerful slash attack similar to Roy's Flare Blade; Flame Nova, a spinning attack that emits fire; Prominence Revolt, where Pyra leaps into the air and crashes back down to create a burst of fire; and Blazing End, a projectile attack that has Pyra throw her sword like a boomerang. Pyra's Final Smash is Burning Sword, in which Rex appears and the two create a pillar of fire that burns and launches opponents.

Prior to being revealed as fighters, both Pyra and Mythra were Legend-class support spirits. Pyra's spirit battle involves fighting Lucina in a red costume, representing Pyra, and Shulk, representing Rex, on the Battlefield form of Halberd. When equipped, Pyra's spirit increases the damage dealt to Assist Trophies.

Trivia

 * Like female Corrin and Bayonetta in the series, Pyra's design added some skin tights covering her legs in her in-game model and artwork. Unlike her counterpart Mythra, who received the same treatment in her in-game spirit, Pyra's in-game spirit has never been modified to add skin tights covering her legs.