Nah, you can go nuts with those situations. I'm currently working out the story though; see Omega as some kind of Loki in The Avengers. Everybody has their own stories, friend and villians, but the main story is going to be about Omega and his 'evil plan'. So, in short, go nuts with your origin, just don't make it a robot nazi dog who curses in Latin and kills people by looking in the mirror whilst throwing explosive strawberries.