Previous Story:
Bayman is his code name. He is not an official character in DOA2 and has no involvement in the storyline. He first appeared in the first "DOA World Tournament" as an assassin hired to kill the organiser, Fame Douglas, also the father of Helena. He accomplished his mission and therefore didn't come back for the second tournament.

DOA3 Story:
This professional assassin acquired his commando-style martial art in the military. Donovan, who once requested the task of assassinating Fame Douglas, had sent a sniper to kill Bayman. However, Bayman easily disposed of the sniper, as he always does. In retaliation against his former client, Bayman decides he'll begin by showing up for the "DOA3 World Tournament".