It seemed that Sams Winchester will have a hard time curing Demon Dean on the tenth season of "Supernatural" because of the Mark of Cain.

Demon Dean is not an ordinary evil entity as he was not possessed. Moreover, he is extermely powerful because he bears the Mark of Cain, although it was not explained what role it will play in Dean's current state. Trying to figure out how to remove the Mark of Cain will be one of the central themes of "Supernatural" season 10. It was suspected that if the Mark does not need to be removed in order to heal or restore Dean back to normal, it may cause a different issue that will be revealed this season.

Show runner Jeremy Carver explained to Entertainment Weekly why Sam will have difficulties in treating Dean. First, there is no demon possessing Dean. It was his own soul gone twisted. Moreover, the Mark of Cain served as a puzzle that needed to be solved.

The showrunner also revealed that another person is looking for Dean. He said that the character's name is Cole who is someone from Dean's past who was looking for Dean for a totally different reason. This guy has not idea that Dean has transformed into a demon.

Zap2it cited Jeremy Carver who said, "He's a guy that has a terrific amount of hunting skills, but he's not a hunter in our sense of the word. He has no idea that the monster world exists, so imagine his surprise when he comes across the man he's been hunting and he is something other than human. He's a pretty cool character."

However, the producer did not reveal any information what would be the fate of this character. The role of the character Cole has not been revealed yet. The producer did not spill any casting news.

"Supernatural" season 10 will be back on air on Oct. 7 at CW.