In the fifth episode of the Demon Slayer: Kimetsu no Yaiba Mugen Train Arc , titled , the battle against the Lower One demon Enmu reaches its climax as the demon slayers attempt to protect the train's passengers. Key Plot Points
Zenitsu protects Nezuko and several cars using his Thunder Breathing: First Form while still asleep. Kimetsu no Yaiba: Mugen Ressha-hen Episode 5
Having fused his entire body with the Mugen Train, Enmu uses fleshy tentacles to attack the 200 passengers simultaneously. In the fifth episode of the Demon Slayer: