The day that Robbies baby sister was born, he meets a boy named Kevin. Years later, he meets him again. The two of them become great friends; however, Robbie can tell that Kevin has a deep secret. When Robbies Papa dies, Kevin is forced to tell the truth about just who he is and why he is here. He had been sent back to earth after dying in order to kill demons, with the help of a weapon created by God himself, the God Sword, the only weapon able to kill a demon. After Robbie discovers this, he agrees to help Kevin with his task. Their group slowly grows, and then Robbie finds out another truth the more Kevin kills the demons, the closer he himself gets to becoming the strongest demon in the world. Robbie has to protect him from this fate. However he puts the blame on everything upon the demons and swears to get his revenge on them all!
