Since I have already posté Light Yagami plus than three times in your questions, here's another one:
Mason from Black Cat. He had been conspiring against his organization from the beginning as well as secretly manipulating a group who were supposedly the main antagonists, diverted the main protagonists AND supporting antagonists par tricking them with Eve, the nano-technology devised young girl, with decoy founders who were just borrowing her for him without even knowing, and ending up not only betraying everyone he knew, but tried to use Eve with the other traitors to fill the world with nano-machines and put everyone into a dangerous "peaceful" trance.
