The battle on the roof had already been settled.
But inside the carriages, the war between humans and demons had only just entered its most brutal stage.
Slash!
Tanjiro severed three fleshy tentacles lunging at a child with a single slash, but almost at the same time, five, then six more surged out of the floor and walls.
The flesh seemed endless, regenerating at a despair-inducing speed.
"Beast Breathing, Seventh Form: Spatial Awareness!"
Inosuke roared and plunged both swords into the floor, sensing the positions of the surrounding enemies through the vibrations traveling along the blades.
"This way! Five at three o'clock! More overhead!"
Although his senses were precise, there were simply too many enemies.
Nezuko and the still-sleeping Zenitsu each guarded an area as well, but everyone had already suffered multiple injuries, and their stamina was draining rapidly.
They could barely manage to protect the passengers, yet could inflict no substantial damage on this enormous demon.
Just as Tanjiro began to feel a trace of discouragement, a voice as bright as the sun pierced through the howling flesh and the passengers' screams, reaching him clearly from the rear carriages.
"Young Kamado! Young Boar's Head!"
It was Mr. Rengoku's voice!
"Don't give up! Set your hearts ablaze!"
Tanjiro looked back and saw that the five rear carriages were already engulfed in a sea of fire.
Kyojuro Rengoku stood like a god of war wreathed in flames. Every swing of his sword whipped up towering fire, forming an impassable defensive line that kept all the passengers safely behind him.
"This demon's body is the entire train! But as long as it's a demon, it must have a weak point-its 'neck bone'!"
"It must be hidden at the very heart, in the most heavily guarded place! Find it! Then cut through it!"