Albert Valentine
Alluring Evil
Carlos, James and Rain were all characters with potential that really didn't deserve to die like that. Would have added to the movies a lot of spectacle and value. Also L.J., who added the humor factor. William Birkin was portrayed shortly in flashbacks and would've played a major role but was cut off. Together with Sam Isaacs, who I think would have portrayed better Wesker - height, looks, voice and acting just fit.