15. He F***ed Up The Marvel Universe
Wolverine has always let his temper get the best of him, and that caused huge problems in Brian Michael Bendis' critically panned Age of Ultron (which the movie will thankfully only draw inspiration from in name alone). When Ultron took over the world and killed most of the Marvel Universe's heroes, Logan decided that the only way to save the future was to go back in time and murder the robot's creator, Hank Pym. This just makes things worse, so he goes back again to stop his younger self killing Pym. As a result, the X-Man must then kill the other Wolverine. How he does so is never revealed, but it caused huge rifts in time.