*Mutant Massacre appearances: Uncanny X-Men #210-213, X-Factor (Vol 1) #9-11, New Mutants (Vol 1) #46, and Thor (Vol 1) #374.
Mister Sinister's agendas have always been mysterious, but none more so than the Mutant Massacre. gathering a cadre of killer mutants, Sinister unleashed these Marauders upon the Morlocks, a mutant band living in the sewers under Manhattan. Despite the best attempts of the X-Men, X-Factor, and Thor to halt the cruel rampage, the Marauders slaughtered half of the Morlocks, and crippled the Angel, Shadowcat, Nightcrawler and Colossus! Though his reasons for the attack remain a mystery, Sinister's plan to destroy the Morlocks was undeniably successful! *Source: Back of Card