... Lugia... I don't think the term of possesion of a body would be that... well....
I was thinking strong illusion spells that they could use instead of possession (or spells that would actually morph their body to seem human). But some people could go and possess bodies. 

Also, Lugia, for the pop up so to speak... I was thinking more about them being there before, but hiding their presence, not wanting to be judge for some of them and other things. Yes some could just have popped up, but I was thinking about making it that they were there before for a lot of them, cause it would be just that progressively things had been going worst.

I don't feel like making it that oh they suddenly popped up out of no where. I feel like making it progressively worst would be better a bit in this case.