The Mutant Massacre
Mister Sinister's agendas have always been mysterious, but none were more so than the Mutant Massacre. Gathering a cadre of killer mutants, Sinister unleashed these Maraduers 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!

Mutant Massacre Appearance:
Uncanny X-Men #210-213,
X-Factor #9-11,
New Mutants #46,
Thor #374,
October 1986 - January 1987