Jin Seipatsu is a SoulWorker affiliated with the Starry Forest League. He was third and final leader of Grasscover Camp before its downfall. He is a former SoulForcer that become SinWorker and took part in the massacre of the Great Void. He was defeated by Lakasha and was subsequently banished from the Great Void, where he becomes a SoulWorker at the start of the game.
Before the Great Void
Before the Great Void, Jin was raised in a poor family, and would often take a number of part time jobs to help make ends meet and was able to experience a large variety of professions. When the calamity of the Great Void occured, Jin joined a rescue group in an effort to help displaced citizens. However, the Great Void eventually reached the rescue camp and swallowed nearby refugees. In a vain attempt to save the refugees, Jin jumps into the Void to try and catch refuges as they were being swallowed by the Great Void. His attempts fails and Jin enters the Great Void.
The Great Void
After a series of unknown events, Jin joins Grasscover Camp and becomes a SoulForcer. He was able to get along with the members of the camp and provided support and care for the hungry and injured. Jin eventually become one of Tenebris's trusted confidant and was part of the faction that supported the rehabilitation of the SinWorkers. However, Jin had an exceptionally high amount of respect for Tenebris and would often idolize him. He would also get into fights with Iris due her reckless attempts to secure supplies at the cost of the search parties. At some point, Jin makes a promise with Tenebris to protect Grasscover Camp no matter what the cost if Tenebris were to suddenly vanish one day. After Tenebris's sudden disappearance, Jin takes over the leadership of Grasscover Camp despite being a SoulForcer.
After an unknown series of events, Jin becomes a SinWorker in order to keep his promise to Tenebris to protect Grasscover Camp. At some point in time, Jin joins the group of SinWorkers and participates in massacre of the Great Void. He was defeated alongside the SinWorkers by Lakasha and was placed into his own parallel world before exiting the Void. Just as he was able to descend from the Great Void, Lakasha greets him about the changed role and his ability to change it.
SoulForcer Ability: Before Jin became a SinWorker, he was an ordinary SoulForcer ,but his unique SoulForcer ability is unknown.
SoulForce - Passion: As a SoulWorker, Jin draws strength from his desire to save others.
SinForce - Passion: As a SinWorker, Jin's had an obsessive desire to save others with very little concern for other activities.