The Conductor

An alter within Louis' system, forcibly created by Pluto after Louis took on Lovelock's debt to him. He was a demonic entity previously who ran a train that was rumored to go directly into hell itself, but post-plot he's lost his powers. He is now forced to help Louis with coping with the awful memories and experiences that he created, and he's not exactly thrilled about that.

Since previously he just stole Louis' name but then Louis returned to being his old self again, he took his title as his name. He might not have his train anymore but he still has a liking towards them.