Ergh, two characters that both sum up "childishly serious". Wolverine's character is fifty layers of "let's make him more gritty and realistic" in decades of comic book writing, while Kratos should've just became god-Nemesis in the second one and got it over with. I vote Asura, whose revenge-fuelled rage is literally his power source in a battle against almost every mythical being in his universe. He does this without saying "bub", even once, and without mashing an incapacitated soldier into pulp for a key in his freaking POCKET.