Hmmm, ego is really powerful but inconsistent...mogo is pretty badass tho. All I know about him though is that he is a lantern and the few appearances I have seen him always involve him saving the day and straight owning the shit out of everything. But Im sure he has some low showings as well. And Ego is multiple times ftl and has a face so he can bite mogo to death in close quarter planet combat.
Ego 6/10 because he can bite continent sized chunks out of mogo.