Zenitsu protects Nezuko and several cars using his Thunder Breathing: First Form while still asleep.
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 Kimetsu no Yaiba: Mugen Ressha-hen Episode 5
The episode concludes with a "Taisho Era Secret" comedy skit. Kimetsu no Yaiba: Mugen Ressha-hen - Episode 5 discussion Zenitsu protects Nezuko and several cars using his
Inosuke’s sharp senses lead him and Tanjiro to the engine room, where they discover the demon's massive neck bones beneath the floorboards. Kimetsu no Yaiba: Mugen Ressha-hen - Episode 5
This episode is part of the 7-episode television recompilation of the Mugen Train film, which features new scenes and music not found in the original movie.
Having fused his entire body with the Mugen Train, Enmu uses fleshy tentacles to attack the 200 passengers simultaneously.