Chainsaw Man Vol 3

Chainsaw Man by Tatsuki Fujimoto. A Shonen manga rated Older Teen, published in English by Viz Media.

Broke and buried in his late father's debts, Denji hunts devils for the yakuza with his loyal chainsaw-devil dog, Pochita. When a betrayal leaves him for dead, Pochita merges with him, and Denji is reborn as Chainsaw Man, recruited to hunt devils for the government. A wild, violent, darkly funny hit.