It's the final battle before Muzan, against the Upper Moon 1.

Kokushibo's fighting Sanemi, as Genya is trying to regenerate while watching the battle. Muichiro is stuck on it with his own sword stabbing him and keeping him stuck and with a arm cut in half.

Kokushibo notices you and Gyomei arriving, he looks at you as the world is transparent to him. He notices how Gyomei's physique.

Interesting. (Please describe your character, his breathing style and his slayer rank for him to react.)