Name: Aki (Akiza in 4Kids adaptation)
Known as: Black Rose Witch
Deck theme: Plants
Favorite Card: Black Rose Dragon
Akiza, known in the Japanese versions as Aki Izayoi, 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.
In her youth, Akiza caused accidents while dueling, often resulting in people getting hurt or injured. Akiza later attended a Duel Academy as a young teenager, where she inadvertently caused more accidents due to the instability of her special powers. Because of these incidents, she became separated from most people and kept herself away from them. Thus taking on the persona of the "Black Rose Witch". Akiza is later found by Divine, a mysterious looking man who has a profound interest to Akiza and her powers.
Her first appearance was when Luka and Tenpei decide to challenge the Black Rose Witch to a duel. Right then Akiza the "Black Rose Witch" appeared and that's when Akiza first sees Yusei Fudo and his Dragon's Birthmark. She sees Yusei as a challenge since she knows he possesses a mark like hers as well.
Akiza is a participant of the Fortune Cup and faces Jill deLauncebeaux as her first opponent. She wins the Duel with her signature card "Black Rose Dragon" and is then exposed as the feared "Black Rose Witch". Which was Jeager and Rex Godwin's intention. They also wanted Jill to expose her as a Signer, however even though she used her powers in the Duel, Akutsu's D-Sensor didn't receive a reading.
Akiza's next opponent in the Fortune Cup for the second round is the Duel Profiler, Kodo Kinomiya, a mysterious man who attempts to confuse and manipulate her with tragic insights from her dark past. After being pushed to her psychological limits by Kodo, Akiza loses control as her mark is revealed which makes her more unstable than usual. Akiza is victorious and moves on to the final round where she faces Yusei Fudo.
After her first attack against Yusei becomes reality, he angrily exclaims that she enjoys inflicting pain on others. With a slightly insane smile, Akiza replies that she is the "Black Rose Witch," a fearful lady who finds pleasure in other's pain, but Yusei knows that her hidden emotion is something else. Yusei ends up defeating Akiza in the end. Akiza is then taken away from the scene by Divine.
When the Crimson Dragon appeared in the middle of Yusei's and Jack's duel, it showed her, Yusei, Jack, and Luna a vision of the Satellite area being destroyed by a mysterious spider drawing.
Akiza's Birthmark allows her to make any damage done in a duel to her opponent real. So this is why she caused accidents when dueling because she didn't know how to maintain the power.
When Luka and Tenpei decide to challenge the Black Rose Witch to a duel, Akiza first sees Yusei Fudo and his Dragon's Birthmark. She expressed surprise to the fact that another individual also possesses such a birthmark. She notes it as a "wretched mark" before she teleports away from the scene. After meeting Yusei, Akiza changes her outlook on the world. Since they haven't had a chance to talk, she sees Yusei as a challenge since she knows he possesses a mark similar to hers.
In the semifinals, her opponent for the round was Kodo Kinomiya. Despite Kodo pushing her psychological limits, Akiza still claims victory in the duel. Her dragon mark, the left claw, is revealed towards the end of the duel.
Akiza plays a Plant Deck that is "Black Rose" themed. Her cards consists of gaining control of her opponents' monsters and inflicting damage by card effects. It is also aimed at summoning her ace card "Black Rose Dragon", the monster that supposedly led to her alias, the "Black Rose Witch."
Some of these informations are from Wikipedia