Pretty good chapter that confirmed some things.
Basically, Akaza is butthurt because he is only Upper Moon 3, while Douma is 2, and Douma came way after Akaza, as we seen in Gyuutarou's flashback, when Douma was only at Upper Moon 6. And we learned that there is a so called Blood Battle between the Upper Moons that could change the rankings between them, if the challanger succesfully wins. Maybe it's a farfetched idea, but I can see Akaza backstabbing Douma in the future, or even "helping" Tanjirou and co by scheming against him. The chill guy has a religion, so that's sufficient reason for him.
Now, Kokushibou. Glad that he is not some relative of Tanjirou or anything, but almost guaranteed to be a Breath of the Sun user and possibly a former Pillar. No wonder he is Upper Moon 1, since technically he can kill all of the other Upper Moons with his blade. His demon face is really hideous though. Ugh, those eyes!
And my boy, Tanjirou is awake 2 month after the battle with Daki and Gyuutarou just to be greeted by wifey wife Kanao, and possibly Aoi later