Mythra

Mythra is one of the main characters from Xenoblade Chronicles 2. She is an Aegis (or Legendary Blade) that can be wielded by the game's main protagonist, Rex. Like Pyra, whom she created as a different personality of herself, she has a sword form and a human form. Both her and Pyra are set to be 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 are set to release sometime in March. The reveal trailer begins first with announcing Pyra, and during a battle with Link in which Link chucks a Remote Bomb at her, Mythra's voice can be heard saying "Let me handle this". Pyra then transforms into Mythra, and continues fighting with Link, successfully reflecting bombs back at him.

They function as one character, with players having the option to switch back and forth between them, similar to how Zelda and Sheik functioned in Super Smash Bros. Melee and Super Smash Bros. Brawl. Mythra's moves include Lightning Buster, a slash attack that can be charged; Photon Edge, an attack that slashes opponents multiple times; Ray of Punishment, where Mythra slashes an opponent upwards and fires a beam of light downwards; Chroma Dust, where Mythra fires multiple, downward shorts; and Foresight, which acts as a counter similar to Shulk's Vision. Mythra's Final Smash is Sacred Arrow, in which Rex appears and the two rain multiple beams of light on opponents.

Prior to being revealed as fighters, both Mythra and Pyra were Legend-class support spirits. Mythra's spirit battle involves fighting female Corrin, representing Mythra, and Shulk, representing Rex, on the Battlefield form of Gaur Plain. When equipped, Mythra's spirit increases the fighter's chance of landing a random powerful attack.