Archangel

Dude can fly and is, basically, the perfect human being (if a mutant can be called that) – he is at the peak of all human senses, while also possessing some other very useful abilities (such as resistance to lower and higher temperatures, the ability to absorb solar energy via his feathers, and so on). Most importantly, his healing factor is off the charts, so he can take some punishment during combat (he can use his blood in order to heal or even resurrect others).

With his upgrades he is even more lethal, since he can simply fight from a distance. He can shoot razor-sharp poisoned feathers from his wings and he is able to control each and every feather he shoots. And that is something very useful when fighting mutants who can, for example, shoot force beams from their eyes.

In the comics, despite the fact that his powers aren’t too exotic, he is quite a capable mutant. I guess that’s why he was the Death Horseman of Apocalypse. And I guess that his fighting skills will be pretty awesome in X-Men: Apocalypse as well (since one of the set pics show him having defeated the Blob and going against Nightcrawler).