Uncanny X-Men Vol.1 #106
The X-Men are working out in the Danger Room when the evil aspect of Xavier's mind attacks them with versions of the old X-Men. A fill-in issue that Classic X-Men skipped for reprinting. The story that began in Uncanny X-Men #105 continues in Uncanny X-Men #107.
Printed: Aug 1977
Writers: Chris Claremont and Bill Mantlo
Art: Dave Cockrum, Bob Brown, and Tom Sutton
Cover: Dave Cockrum