You are using character designs that are clearly recognisable as characters from the Marvel universe. That's generally a Bad Idea, unless you have a licensing deal with Marvel/Disney I'm not so sure their lawyers will be convinced by bunny ears.
Court maybe, but do you think you have the financial endurance to take it that far? Marvel for sure does.
If I were you, I'd try to make them a bit less obvious.
But maybe I'm just a coward
Anyway, we are going to make unique enemies design, and they won't have resemblance with any other characters.