But, in all seriousness, there wasn't really even a true villain to this story. The brotherhood was just helping Magneto get his dead daughter. Venom wasn't real. Ultron was just a spurned lover. Doom seemed like an after thought.
The only true villain was a terrible script with no foresight whatsoever.
It almost seems like Loab did a mad libs and just filled in "fun" spots and then handed it in as a story.