Everybody's favorite megalomaniac.
Wesker's entire M.O. is to force the evolution of humans by spreading a zombie virus across the world that eliminates the weak and leaves only the strong standing. Or something like that. He's not exactly playing with a full deck of cards... or I guess it'd be more accurate to say he's playing with 4 different decks of cards all shuffled together. He probably thinks it would give him the upper hand on the playing field. In reality, all of the other players of the game are left dazed and confused by his action, which is just what he wants.
In Heaven For Everyone, Wesker is very smug and self-centered. But then again, he's kinda always like that, isn't he? He believes that his plans to take over the world are full proof, and the only way forward for humanity. When Chris shows up on his doorstep to stop him, Wesker is more than happy to "entertain" his "old friend" by sicing a brainwashed Jill Valentine on him. As Chris struggles in a fight with his formerly lost best friend and partner, Wesker launches into his usual theatrics and gloating. He's just that kind of villian.
Voice Type: Smug, Pompous, Self-Centered
Personally, I feel that William Dafoe's portrayal and voice for the Green Goblin would suit Wesker almost perfectly. A bit of smugness here, a bit of self-importance there, and a whole lotta ham & cheese will go a long way in portraying Wesker.