The Evil Spirit was clearly the village bully who had killed the train conductor's mother earlier.

The passengers once had a chance to leave, but in the end, the village bully caused the conductor's mother's death, leading the conductor to refuse to start the train. As a result, all the passengers on the G19 train perished at the station!

Naturally, this included the village bully.

His resentment lingered, haunting the place, turning him into a fierce ghost like the conductor, and their mutual hatred intertwined them!