Keenan McCall
After doing some research, we have an answer for you.
How Long Did Denji and the Eternity Devil Fight for in Chainsaw Man? Answered
The short answer is that Denji and the Eternity Devil fought for at least three days without end in Chainsaw Man. Himeno mentions this when she reports back to Aki about the progress of the fight, and then crawls into bed with him. She also says that she isn’t sure though, which is understandable given that the Eternity Devil’s powers had every member of Division 4 trapped within a separate reality where they couldn’t keep track of the time. Regardless, this means that Denji fought without eating, drinking, or sleeping for several days on end. The reason he was able to do this is that he made a discovery while in his Chainsaw Devil form: So long as he consumes flesh and blood while in said form, he could keep his transformation manifested and heal up any damage inflicted upon him. This proved easy enough to do thanks to the fact that the Eternity Devil was constantly regenerating whenever he cut it. As such, he was able to maintain a cycle of maiming and dismembering the Eternity Devil, consuming its flesh and blood, waiting for it to regenerate, and repeating the process. This in turn is why the Eternity Devil eventually surrenders and asks Denji to kill it. Denji made it suffer through agonizing pain for days on end until it couldn’t bear the thought of being torn apart anymore. This drove it to expose its core, and it died after Denji split the core in half. Hopefully, this cleared up how long Denji and the Eternity Devil fought for in Chainsaw Man. For more on the series, check out any of the related articles down below. we’ve also got plenty of other explainer guides on topics like why the Eternity Devil wanted to eat Denji, what the Eternity Devil is, and whether or not the Eternity Devil knew Pochita.