Mr. Sinister: Mr. Sinister is that potentially lethal combination: a brilliant scientist with near-unlimited powers. The shape-shifting, energy-projecting telepath has been following the life of the X-Man Cyclops since he was a boy, and manipulating it in ways that no one could have expected.

Nimrod: A deadly, mutant-hunting Sentinel from an alternate future where Sentinels rule, Nimrod first came back to the present in pursuit of a time-travelling mutant, and has been destroyed and reincarnated more times than the X-Men can count.