Kaitou (Bandit) Ace is the mysterious masked man who comes to Sailor V's rescue in the manga. Bandit Ace throws cards in the same way that Tuxedo Mask throws roses. "Kaitou Ace" is also a popular television show that Minako loves, about a young man who is called "every girl's best friend". Bandit Ace is played by Saijou Ace, a young man that Minako loves; he was her first kiss. But she later discovered Ace was the head of the Dark Agency, Danburite. It also turns out that Bandit Ace was a soldier from the planet Venus a long time ago, who served in the army of Prince Endymion. His name back then was Adonis, and he loved the Princess of Venus from afar but never dared to tell her, especially when he discovered she was in love with his commanding officer, General Kunzite. Sailor V was forced to kill Danburite/Adonis, who cursed Minako at his death that she would never have a successful relationship with another man, because it was his fate never to find love with her.
Bandit Ace's Powers:
He has a silent transformation, like Tuxedo Mask.
Bandit Ace throws cards. He can do this without saying anything.
Delicious Four-Card Shot! -- Ace throws four aces that cut through enemies.
He can also read fortunes with his cards.
(info taken from http://www.geocity.com/Tokyo/2666/profiles/ace.htm here)
