New Mutants, Vol. 1 #29 (1985)

Meanwhile, Back at the Mansion..
Sunspot and Magma have been captured by Empath's agents and brought into the Gladiators, and they are fighting the best fight they can. When Cannonball and Magik arrive to help, they refuse to be saved for reasons they cannot go into. At this point, Magneto arrives to take leadership of the team and prepare for the Beyonder.
Release Date: 1985