X-Man
Nate Grey came to the Earth-998 from his native reality, Earth-2098, which was sacrificed to restore Earth-998. The Red Queen wanted to use him as an ultimate weapon, but he was dangerously unstable, so she gave him a genetic insignia, to stabilize his powers. In the process of experimentation, his mind was damaged and he went mad. The Queen seemingly slew him, but he actually survived and escaped.