The start of the mugen train arc in the hahsira surplus au!
They've only just gotten here and Tanjiro has already lost 5 years off his life from stress. The context for why Sabito hates Tanjiro can be found here.
When lower moon one attacks, Rengoku initially suggests the same roles as in the movie (him, Zenitsu and Nezuko saving people on the train while Tanjiro, Inosuke and Sabito deal with the demon) but Sabito cuts in and "suggests" that Nezuko should help him deal with the demon instead (effectively swapping Nezuko and Insokue's roles). Especially when there is the threat of a demon, as there might be blood shed, Sabito wants to keep them in his sight. He is taking no chances for Nezuko to attack a person, even if she resisted in the pillar meeting. The stakes are too high for that.
He gains some respect for her when she uses her blood demon art to protect him and Tanjiro from the eyes that put them to sleep. He gains a lot of respect for Tanjiro when he finds out how he escaped the dream land. Sabito on the other hand is able to wake up quite easily, as his peaceful dream feels so wrong because of Giyuu and Urokodaki's recent betrayal and his unease.
Between them, lower moon one isn't really a threat, but upper moon three might still be a problem...
First mugen train post | Au masterpost
