Sheik is a playable character in the fighting video game, M.U.G.E.N Trilogy. She was confirmed along with the others from Super Smash Bros. Melee on February 1, 2015. Instead of Jun Mizusawa from the past Super Smash Bros. games, Ayumi Fujimura (who also voices Zelda, Marisa Kirisame and June) reprises her role as Sheik in this fighting game.
Sheik is a Sheikah and the magically-induced alter ego of Princess Zelda who debuted in The Legend of Zelda: Ocarina of Time. Unlike Impa, the only other Sheikah seen in the game, Sheik's voice is muffled and her face is concealed, which make her virtually unrecognizable.
Sheik first appears before Link soon after his spirit is unsealed after being contained within the Chamber of Sages for seven years. Upon meeting Link, Sheik reveals that now that he is old enough to properly be the Hero of Time and has acquired the Light Medallion from Rauru, the Sage of Light, he must also awaken five other Sages and acquire their respective Medallions in order to become powerful enough to stop Ganondorf and save Hyrule.
Following this, Sheik appears before Link at various instances, and uses her harp to teach him warp songs to help him on his quest. In addition to teaching Link the songs, she imparts words of wisdom to him before mysteriously disappearing each time, typically via the explosive flash of a Deku Nut.
When all six Sages are awakened, Link arrives at the Temple of Time near the end of the game and is greeted by Sheik, who uses the Triforce of Wisdom to reveal herself as Princess Zelda. It is generally assumed that Sheik is a magically-induced transformation.
How to Unlock
Use Sheik's Super Smash Bros. amiibo or scan Sheik's AR Icon from the M.U.G.E.N Trilogy website.