Read comic: X-Men: Fall of the Mutants

comic
Summary:

Two teams of mutants. Two tales of tragedy. The vicious Marauders have already slaughtered the tunnel-dwelling Morlocks, and now they plan to kill Cyclops' estranged wife, Madelyne Pryor! And if that means taking on the X-Men, that's just fine with them! Meanwhile, Storm goes on a vision quest to find Forge...but she discovers the evil Adversary pulling their strings, and the X-Men will need to literally sacrifice their lives to stop him! Meanwhile, the New Mutants take in the hybrid creature known as Bird-Brain... but when he flees back to the island where he was created, the team follows and clashes with the Ani-Mator.