Chainsaw Man chapter 64, "Welcome to Hell," marks a pivotal shift in the International Assassins arc with the introduction of the Darkness Devil, a "Primal Fear" that incapacitates the main characters. The chapter is defined by Lovecraftian imagery, including bisected astronauts, and sees Santa Claus initiate a deal for Denji's heart to kill Makima. For a detailed breakdown of the events and imagery, read the Chainsaw Man Wiki analysis .