User blog comment:Tommy,Klaus&Kol2012+/Unanswered questions/@comment-98.125.234.38-20161023142008

The History of the Mark & its purpose was fully explained, but there's a few bits that need explaining. First, God trapped his Sister (Darkness, cause he's the Light) in the Mark. The Mark later corrupted Lucifer, turning him into the Devil. Then Cain makes a deal with Lucifer to save Abel's soul, Cain is given the Mark, Cain later offs his brother, Cain then bcomes the 1st Hell Knight. MUCH MUCH later. Cain passes on the Mark to Dean.

Now the question comes in: Cain no longer has the Mark, it was the primary thing keeping him alive and the primary thing that turned him into the Murderer he is known as. Cain somehow becomes more bloodlusting without the Mark, is still more powerful than Angels & Demons, and it takes Cain bone blade with the Mark to kill him for good.

Fast forward to where Dean became a Demon, then lost the Mark by freeing the Darkness. Why isn't Dean affected the same way as Cain & Lucifer? They both had the Mark, they both past is on to a successor, but despite losing the Mark, they still remained Evil & blood thirsty. So shouldn't Dean be a blood thirsty maniac with powerful demonic powers (Cain became a powerful demon the same way Dean did an somehow kept his humanity just like Dean) too?