Another dangerous path to thread. The more superior creatures you mention, the more I (and you readership) want to know WHY in the first place they all want to have something in common with your "usual people". Would you deal with small kids in the same way as you deal with adults? Would you condescend to children and intentionally restrict your abilities while playing with them? Yes, you can invent a good motive, but it requires very careful planning of the background. Remember that life-like characters aren't compatible with a scenery made of painted tissue paper.
Well, I got the idea. Can't say much about it without knowing the details. However, you have to answer a simple question: why your readers would be interested in a just another Captain America? Is there an element of surprise? Stereotype thinking won't do any good to you and your book.
The character is nothing like Captain America. All I was trying to do was give an idea of power level. And by the way, the real superiors stay offstage. Their only real part in the story is to give some sort of reason for Homo Superior to be where she is, at all.
I agree with you that characters in a book with demigod power level are very hard to handle - and many authors, including published ones, can't handle them very well. There is also a tendency to solve problems with the story by revealing new powers. Witness the ridiculous levels to which DC Comics characters climbed - also Marvel to a lesser extent.