guy steals a pot that has demon souls for his gf. They are unleash. His family is hated and dad is crippled. Finds out the gf is working for some other clan. One souls get attach to his body and saves him from his gf attack. The soul gives him powers but the more he use it the more chances of soul to take over him. Meets a guy tells him he can choose one item from his stand. He choose book. In the book lives a girl that helps him. Can't remember anything else about the novel.
http://www.novelupdates.com/series/peerless-demonic-lord/ It's Peerless Demonic Lord but sadly translation has stopped at 29 chapters