Demon Emperor Prodigy System

Where The Legendary summoned heroes story ends with betrayal at the hands of his allies, another one is born. The now dead hero is given a second chance at life. "Welcome to the interdimensional system" As a fallen hero Arthur is given another chance to rebuild his strength while living through a life of a young to be Demon Lord Lucifer. Split between dimensions Arthur has to settle his grief and prepare to take his revange against those who wronged him.