Hmmm... if we're talking about exceptionally powerful psychic types: what about this guy? I've talked about him before in this board.
He was the product of Magneto's evil infecting Professor Xavier and possessed both their power sets: immensely powerful telepathy and control over magnetism. A little while later he captured Nate Grey and Franklin Richards, two mutants with immense psychic abilities and the power to alter reality, and took their powers for his own. He took on all the heroes shown above, plus the X-Men, and was defeating them all until a bunch of them sacrificed themselves to contain his life force and destroy him. His powers, at their peak, were enough to make a second sun appear in the sky.
He's not a very complicated character - after all, he's not a person, but more of a sentient psychic tumor, consisting only of hate. At first he wanted to destroy all the humans so that mutants would inherit the Earth, but when he read Nate Grey's mind, he discovered that in the alternate timeline he came from that had already happened, and the world had been destroyed anyway. So he decided he would simply kill everybody in the world.
I really wonder what an all-out battle between him and Archanfel would be like.