Summary
The Mugen Train Arc in Demon Slayer was easily one of the best arcs in the series, making it a massive box office success. The Mugen Train Arc received widespread critical acclaim because of its exceptional animation quality and storytelling. The success began in Japan and traveled worldwide, capturing the hearts ofDemon Slayerfans internationally.
The plot follows Tanjiro, Zenitsu and Inosuke along with the powerful flame Hashira Kyojuro Rengoku who boarded the Mugen Train to investigate a series of disappearances. Lower moon one demon, Enmu serves as the main antagonist of the arc, but who really was Enmu?

Enmu’s Troubling Early Life
As a human, Enmu was no different from when he was a demon, he was a menace to those around him and had problems telling the difference between dreams and reality. He would go around pretending he was a doctor andhypnotized people into believingthat they were cured even though they did not have long to live. He later tells them that he lied and that they were in fact dying, he enjoyed seeing the look of fear and sadness in their faces. This type of behavior did not bother him because, as by nature, Enmu was an extremely sadistic person and he cared less for people. He prioritized his pleasure and enjoyed seeing people suffering. Muzan recognized the potential Enmu had, so instead of killing him, he turned him into a demon.
The difference between Enmu and other demons was that he did not exactly come from a difficult human background. Most of the demons in the series faced hardships as humans and wanted to become demons because they wanted to enact revenge or just become powerful. Enmu on the other hand,had no such experienceand becoming a demon for him was just an upgrade to his vicious nature.

The Dream Demon
Enmu was the only lower moon demon who survived the massacre after Muzan had killed off all the lower moons for not performing as he expected. Muzan was pleased with Enmu’s response when he asked Enmu what his last words were. Enmu stated that he was happy dying by the hand of Muzan and that he enjoyed seeing his peers suffer. Because of this,Muzan gave Enmu his bloodto become stronger. Enmu became so strong that he was able to warp his body with a train and was also able to put more than 200 passengers on the train to sleep.
Since Enmu was classified as a lower rank one demon, this meant that he was the closest to the strength of the upper rank demons. One of his other powerful abilities was being able to manipulate his target’s dreams once he put them to sleep. He is able to manipulate dreams and chose what he wants his victims to see. He chooses to show his victim happy dreams or nightmares and psychologically attack the victim in their subconscious, this was his favorite form of torture. His goal is to make his victim feel his or her dream is real. However, his blood demon art is useless for victims who have a strong will, as they are able todistinguish dreams from realityand realize they are not in the real world. This is seen when Tanjiro realizes this and commits suicide in his dreams in order for him to awaken. Enmu also had the ability to manipulate his own flesh in whichever way he wanted, this enabled him to detach certain parts of his body but still control them. He was able to detach his hand and communicate and see with the eye and mouth on it.