User blog comment:Jenses 4.0/Who Is The Greatest Villain of the Supernatural?/@comment-4256259-20121014102657/@comment-3481504-20121015163614

Without his older brother, Michael....in his vessel....he would've effectively taken over the world, and eventually the Universe. Like literally, it's described that only God and Micheal are capable of defeating him. Although, Death too is stronger than him.