Those poor Cuckoos. their power comes from their connection to each other, but they keep getting killed off. Down to three, they were weiling a shard of the phoenix force, but it “mysteriously” abandoned them just as Hope Summers returned to the present timeline.
Nathaniel Essex was rediculously overpowered, and for quite a while nigh immortal. Of course now he’s Miss Sinister, or rather he’s transfered his powers to his daughter. We’ll see how that turns out (watch for her in the new X-23 ongoing).
It’s hard for me to think of any incarnation other than early 90’s, leader of the Marauders Sinister. That was when I first started reading comics and X-men was the only book I read for years. I’d say he could handle the three-in-one with phoneix force comfortably. Telepathy, TK and a healing factor – his powers eclipse theirs.
Freedumbring 