[jiggaj]

i'll start
jack mort=drawing of the three
The Pusher. In The Drawing of the Three, Roland enters the third door and into the mind of the man responsible for both Susannah's multiple personalities and loss of legs. But most importantly, he is the one who pushes Jake Chambers into the car, the event that brings him to All-World. Roland stops this event, unknowingly beginning a long chain of events climaxing for the time being in The Wastelands
What we know about Jack is that he is a sadistic CPA who creams his pants by pushing people to their deaths, or by "pushing" objects onto them. These attacks are acted upon seemingly random people, with the only stated motivation being to twist fate any way he can by maiming and/or killing people, and thus, ruin their otherwise productive lives.
The most remarkable accomplishments, however, are his two seperate attacks on future gunslinger Odetta Holmes. His first attack on Odetta was when she was a young girl. Mort was hiding in a building a few stories above her and dropped a brick on her head, causing serious brain damage that would cause the creation of her split personality, Detta Walker.
Decades latter, when Odetta had grown up, Mort pushed her in front of a train without any idea that she was the same person he had attacked years before. This coincidence, however tramatic, may have been an indicator of the entwined destinies of those behind the magic doors Roland encounters on the beach.
Roland uses his body to get Keflex and ammunition for his guns, and then gives the man what he deserves by hopping in front of a train, which had cut the bottom half of Susannah's legs, as he leaves Mort's body. The train, however, cuts off more than just Jack's legs. It cuts him in half.