Uncanny X-Men Vol.1 #136
The X-Men set out to stop their out-of-control teammate. But do they possess the power to stop the Phoenix gone mad? Don't bet on it. Enter: Professor Charles Xavier. Can even the most powerful mutant mind on Earth stand against a creature that can consume stars? Mankind's further existence depends on the outcome of this clash of titans.
Printed: Aug 1980
Writers: Chris Claremont and John Byrne
Art: John Byrne and Terry Austin
Cover: John Byrne, Terry Austin, and Jim Novak