Er, Legion can not only blink out all the individulas you mentioned, he could blink out all of 616. And he did before.
As for the Elder Gods you should maybe read up on them. Like Gaea, Set or Chthon. They pretty much created life on Earth, created the oceans, created demons, killed the dinosaurs, etc. Y'know, nothing big or anything. lol featz
Bishop's tough as ****. He could kick Magneto's ass too tbh. Especially like a hundred years ago when Magnus was also a scared damaged teenager.
Wolverine never cut Legion's head off though, and even if he did it likely wouldn't matter. Unlike Magneto, David doesn't really have limits.