Tastes like boozey vomit.
So, Denji battles the Eternity Devil, and finds that he’s rather capable of maintaining things well. As much as he may wear down or get injured, consuming the blood of the devil regenerates him. It is, as he puts it, a perpetual motion machine, and that motion consists of chainsaws being applied to the Eternity Devil’s flesh. After a few days of this, the Eternity Devil gives up and exposes its heart so that Denji will kill it – anything to make the hurting stop.
As the battle was being watched by Himeno (eyepatch senpai), we get her flashback to talking with her mentor about what makes an effective Devil Hunter – namely, the extension of the idea that the ones that are most effective are the ones with at least a screw loose. The sane ones fear the attacks of the devils, which empowers the devils and leads to their demise. As Himeno sees it, both her and Aki are too sane to bring down the Gun Devil. Denji, on the other hand…
With the Eternity Devil defeated and a bit of Gun Devil acquired, the whole team goes out drinking to celebrate an all-too-long job well done. They eat, they drink, Makima shows up, and it turns out Denji needn’t have worried about getting his reward kiss since Himeno is infamously friendly (and frisky) while drunk. Or perhaps he should have been more worried, since “kiss with tongue” turns into “throw up right in Denji’s mouth”, much to the horror and/or amusement of Denji’s coworkers.
Denji, who we find out is sixteen, also ends up drunk or at least hung over from the second hand booze, and is feeling the worst effects after he’s hauled… somewhere like home? Somehow he ends up somewhere Himeno identifies as her room (I don’t recall the backgrounds well enough to say if it is or isn’t), and she comes in and ends up propositioning him in a still rather drunken state herself.
Somehow, I don’t think that’s going to work out for him. The pursuit of the Gun Devil is more likely to have a good outcome, and given the tone of this show I wouldn’t guarantee that being painless.