She is Mafuyu Asahina. Depressed, wanting to disappear. "Mind F#$&" - Mafuyu stuns 相手 and forces them to feel her pain. "Flash Fury" - Mafuyu slashes with her knife at a fast speed. "Knife Impale" - Mafuyu grabs 相手 and stabs them in the guts, dealing bleeding damage. "Nonexistence" - Mafuyu fades from reality, rendering herself invisible to 相手. She can also fight normally with her knife.