Sayaka Miki (美樹 さやか Miki Sayaka) is a classmate of Madoka Kaname, she became a Puella Magi after the wish to heal the wounded hand of Kyosuke, a violinist who inspired her since childhood. She uses a sword to fight, can create copies of her weapons like Mami Tomoe and has exceptional healing ability.
In M.U.G.E.N, Sayaka Miki has been made by otzkai and Annri.
Annri's version is a five-button character with weak but fast attacks and a variety of techniques involving her swordplay and a magically-augmented bat. The character's Hypers, while quite damaging, are also hard to land, and her magic-based attacks are exceptionally good at dealing damage and getting through the defenses of more guard-happy enemies.
Sayaka has an unusual mechanic where she will automatically lose the match if the Soul Gem situated at the bottom corner of the screen turns black and into a Grief Seed, which happens once the gem's energy has been fully depleted due to the continued usage of certain attacks that drain it; the Soul Gem's energy does not seem to be able to be recharged manually, with the only situation in which it gets recharged being if Sayaka loses the previous round via running out of Soul Gem energy, causing her to start the next round with less than half of it.
Annri's version of Sayaka has a large number of unused sprites present in her sprite file, including a set of sprites for being de-aged by Alessi's stand, Sethan, although this is never used due to the only version of Alessi made for M.U.G.E.N using sprites from their own spritesheet when a character is de-aged.