User blog comment:DaSuperNaturalist007/Supernatural- The Ideas-/@comment-5619706-20131114032109

Here's something new and possible within what we have right now--a dark prophet. Either Kevin gets killed off or gets corrupted by a number of rituals and demonic blood transfusions. Because of the screwed up structure of Heaven, prophets no longer enjoy the same level of connection with God and thus could be corrupted to serve Hell. Instead of writing down God's commandments or true prophecies, they enter a trance to speak false ones that become self-fulfilling. Basically, if he says that he will have the ability to teleport then it will come true. The greater the reality warping, the more energy the dark prophet expends (so there is a limit to which he could use his ability). Basically he could be as powerful as a cambion.

He is fed an overwhelming amount of souls and demons (not unlike famine) to keep him powered up. Cutting off his supply would weaken him. Angelic abilities are useless against him as he maintains a certain degree of divine protection, and at the same time, is rendered immune due to the massive amount of demonic energy he's holding. (This would open up doors for different allies for the Winchester). He is most vulnerable during a trance.

Basically, his role is to act as 'the Dragon' (trope) of the 'Big Bad', but he could become a 'dragon ascendant' to become the Big Bad himself.