"not enough died" - Ghoul's sadistic calling card.
Ghoul was a Marvel super-villain who debuted after the events of Scarlet Witch depowering almost all mutants on Earth, driven insane Ghoul went on a bloody rampage as a serial killer targeting other mutants, believing he was pure since he managed to retain his powers he saw other mutants as weak and began sadistically killing them.
Ghoul's signature calling card was a note left behind at each murder stating "not enough died" and he wanted Sally Floyd to report on his murders, since she was performing many stories on mutants and former mutants as part of a humanitarian effort (herself losing a child to the depowering spell).
Ghoul would ultimately be killed when Floyd managed to convince Archangel to act as bait, luring Ghoul out and in a twist of fate the serial-killer became the prey and was killed.
Prior to his death he had pyrotechnic powers and an ability to teleport as well as a grotesque, inhuman appearance often associated with Morlocks.