MEPHISTO

The trap was set by accident in Fantastic Four #276 (1985), during John Byrne's run, when a self-appointed exorcist named Elspeth Cromwell decided Reed and Sue Richards were a witch and a warlock and spilled innocent blood trying to purge them. The ritual summoned the genuine article. Mephisto dragged the couple into his own nether realm to torture at leisure — but he handled their young son very differently from his parents. Franklin Richards was kept unconscious inside a diamond-like cage, because the lord of that realm had measured the boy's mutant power and wanted no part of it awake.

Doctor Strange followed the Richards family into Hell and read the situation instantly: the cage existed because Mephisto was afraid. Strange and the parents freed the boy, and Franklin woke up facing the thing that had caged him. His eyes lit, and he fired. The first blast staggered Mephisto on his own ground, where his power should have been absolute; the second, in Fantastic Four #277 (1985), annihilated him outright, sending ripples through the dimension that sprang other captives — including the sorceress Topaz — from their prisons. A child in pyjamas had done, in two shots, what archmages and cosmic heralds had failed to do for decades.

Hell-lords rarely stay destroyed, and Mephisto duly re-formed out of the evil lodged in human hearts — but he came back incomplete. The blast had split his soul into scattered fragments, and the fragments kept working mischief without him. The demon-tricked Master Pandemonium spent years hunting the pieces believing they were shards of his own traded soul. Worst of all, two of the fragments had been caught by the Scarlet Witch's hex magic and given life as her twin sons, William and Thomas — which is why, when Mephisto finally reabsorbed his missing pieces in Avengers West Coast #52 (1989), Wanda Maximoff's children ceased to exist, a wound in Avengers history that traces straight back to a small boy opening his eyes in Hell.