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...
He said he believes in you, so just think
about how you're going to measure up to that!
¡Dijo que confiaba en nosotros!
¡Dijo que tenía fe en nosotros!
Ele não te disse que acredita em você?