The demon that appeared before Tanjiro and Rengoku after they defeated Enmu was the Upper Three, Akaza. While injured and on the ground, Tanjiro is almost attacked by Akaza and narrowly escapes death when Rengoku quickly strikes back. During the intense battle between Rengoku and Akaza, Akaza suggests to Rengoku that he should also become a demon. Rengoku vehemently refuses Akaza's offer, but his injured body is exhausted and being pushed past its physical limits...
Any other Hashira
would've done the same thing.
Cualquier Pilar habría hecho lo mismo.
Cualquier Pilar habría hecho lo mismo.
Qualquer outro Hashira teria feito o mesmo.