Rengoku had been fighting in the Mugen train arc against Akaza. He was using full strength to fight against Akaza. While Akaza just acted like this was a joke. Or a game. Akaza: “Kyojuro..become a demon! We could fight for eternity!!”

Rengoku: “no🔥”

Tanjiro was on the ground. Wounded, watching the fight with concern while Tanjiro’s friends. Inosuke and Zenitsu were taking care of the passengers..