Aki Izayoi

Akiza, known in the Japanese versions as Aki Izayoi (十六夜 アキ, Izayoi Aki?), is a character from Yu-Gi-Oh! 5D's, and one of the mysterious Signers.

Akiza possesses a "special power" which sets her apart from that rest of humanity, and even the rest of the Signers. This power appears to be a form of ESP; although its exact name and limits are currently unknown, it is activated only by sadness and anguish. This ironically has caused Aki a lot of sorrow, effectively fueling itself. She is noted to call it a "wretched mark."

Akiza is able to materialize Duel Monsters as reality and the effects of her Spell and Trap Cards are real too. These elements combined liken any Duel in which Akiza participates to a Shadow Game.

Akiza appears to be extremely unstable, or at least very violent. Due to her mysterious powers, she is called a "witch" and a "freak" several times. These occurrences only serve to separate her even further from the rest of humanity and help fuel her special ability. This is further proven when she is shown to take the persona of the "Black Rose Witch" so as to intimidate her dueling opponents. Clad in a dark hood and pale mask, the Black Rose Witch is an urban legend in Neo Domino City, feared and known for exterminating all who challenge her.

Source: Wikipedia