Paul WS Anderson took a look at the lore of the Resident Evil games and said "This is all stupid. Let's make it about what if scientists gave my hot wife super powers instead." You kind of have to respect it.
Generally, storytelling involves events following logically from one another, or from the characters' actions, but Anderson et al sort of eschew all that in favour of things just happening that are, at least in theory, sick as hell.
Mike Epps is in a completely different movie from the rest of the cast, and clearly having a lot more fun for it.
