Uncanny X-Men Annual, Vol. 1 #11B (1987) Newsstand

Lost In The Funhouse
A new villain named Horde arrives at X-Mansion to recruit the team for his own purposes. An object of great power is trapped within a citadel, and he needs surrogates to claim it. His power is so great, that the X-Men are forced to comply and deal with the citadel themselves.
Release Date: 1987