The Leader has since proved himself to be an adversary of humanity and has made many attempts at world conquest. He has continually been thwarted in his schemes by the Hulk, his greatest nemesis. When last seen, the Leader had gone back in time to primeval Earth in a mad scheme to create a divergent Earth whose history would differ from his own Earth's. The Hulk and the Avengers followed him back to that time period to stop him. In the course of their battle with the Leader, the Hulk and Avengers saw him fall into a volcano, and the Avenger Iron Man saw him fall into the molten lava within. It appeared that the Leader was finally dead.