X-Men: Dark Phoenix Saga

An epic tale of triumph and tragedy! When the Dark Phoenix rises, suns grow cold and universes die! Gathered by Charles Xavier, the X-Men have dedicated their wondrous abilities to protect mankind - even those who hate and fear them. one of their own, Jean Grey, has unwittingly attained power beyond conception - and been corrupted, absolutely. The X-Men must decide: Is the life of the woman they cherish worth the existence of an entire universe? This touching tale of ultimate power and the triumph of the human spirit has been a cornerstone of the X-Men mythos for over three decades.
COLLECTING: X-Men 129-138, ClassIc X-Men 43, Bizarre Adventures 27 (1st story), Phoenix: The Untold Story, What If? (1977) 27