Bruised & Battered

Kishibe lets the limp Denji and Power fall, explaining that their bodies mirror human anatomy closely enough that breaking their necks merely paralyzes them. He then feeds them blood, since for devil-touched beings that alone mends nearly any wound. Calling himself the strongest hunter alive, he insists real training means pushing the two until they can actually defeat him. The moment they ready an attack, he stabs Denji through the head and back and opens Power's throat, praising their inhuman instinct to lunge without hesitation. He recalls wishing since childhood for a toy that would not break and vows to forge them into the baddest of badasses.

In his hospital bed, Aki cannot rouse the Fox Devil with his usual call. Kurose suspects the spirit resents being wounded by Katana Man and will never answer again. When Tendo probes how the Curse Devil has shortened his life, Aki cuts in to demand their purpose. They explain that with the Devil crisis worsening and the organization gutted, leadership wants him to contract a vastly powerful Devil. Offered the chance to quit for a calm life, he refuses, set on avenging his family against the Gun Devil and Himeno against the agents. As they go, an unseen woman steps in, startling him. That night Kishibe ends the session to sleep, and the battered pair limp home, Power tallying that Denji likely died twenty times. Weighing escape, they instead resolve to outthink rather than overpower their master, and the prospect leaves them feeling smarter already.

Kishibe reveals devils recover from blood and trains Denji and Power through repeated lethal injuries. Aki permanently loses access to the Fox Devil and is steered toward contracting a stronger Devil, refusing to quit out of a thirst for revenge. A mystery woman visits him, and the trainees decide to outsmart Kishibe.

This fourth-volume chapter of the Katana Man arc appeared in issue 2019-33 on July 13, 2019 and was adapted in episode 10. It sets up Aki's coming Future Devil contract and frames Kishibe's mentorship as deliberately brutal conditioning.