Can you post a list of things that are allowed or are not allowed? That would be helpful in coming up with a plan that would work. Sorry for the trouble.
It is alright, I think it can be a good things to have. So, here we go
Requirements of character:
1)humanoid body. You don't have to look exactly like a human, but things like an orb of energy or a superintelligent shade of blue are not allowed.
2)you need to have some sort of combat ability. This could be derived from a thing other than your powers, but having a non combat outsider superhero character in the the 1920 Germany will end badly.
3)you can't have a major former knowledge human society. Basic knowledge is okay, but having mapped out Berlin and surveyed the current state of Germany not. You have knowledge of an outsider, though you may be an educated one
4)you must have had existed before arriving on earth, Or have another source from which you have gained your skills, knowledge, and at least extremely basic knowledge of life(not human society knowledge, but really, really basic things, which most would learn as child's in one way or another).
5)lastly, your powers need to be able to work in the Mutants and masterminds rules, simply because they are the mechanics used to run the quest
There is no ban on human characters though, as long as they come from outside human society, from somewhere unknown to the rest of the world
Also, it is interesting that every plan is based on alien origin. It is the type of superheroes I am the least experienced with, so I might have difficulty to handle this. It shouldn't be that terrible, and will probably improve with time, but do note that there might be a few problems at first