Uncanny X-Men Vol.1 #134
The X-Men finally turn the tables on their captors, but too late to help Jean Grey. For months the Master of Illusion, Mastermind, in the guise of Jason Wyngarde, has been psychically seducing Jean. However, his mental tampering has unleashed the most dangerous creature this universe has ever seen. Thus, the Dark Phoenix is born, and no force on earth may be able to stop her.
Printed: Jun 1980
Writers: Chris Claremont and John Byrne
Art: John Byrne and Terry Austin
Cover: John Byrne and Terry Austin