Uncanny X-Men Vol. 2: Dominant Species

It's once again time for the X-Men to mutate. First, will Juggernaut -- one of the X-Men's toughest foes -- actually join their ranks? Then, as the high-flying Archangel goes through a major physical transformation that affects his powers, he encounters a threat to his family corporation.

Collects Uncanny X-Men (1963) #416-420.