the cape doesn't look well done, I mean the wrinkles are not ok! I advice you to use gradient in a good way and not in that way! because it looks awful in that gradient and it's noticeable! if that background is going to be used in the animation ! don't do it! because it's not that much good!
A good way to use a gradient in animation is to use a normal color to cover it up! it can't tell you how to cover the normal colors because I usually do it through trail and error!
instead of gradient in background why don't you use normal colors!