Mark of Cain

The Mark of Cain.

The Mark of Cain is a brand placed on Cain by Lucifer. It is the source of the First Blade's power. The mark and the blade work together, and without it the First Blade is rendered useless. The mark can also be transferred if the person is worthy of it, i.e. a killer. According to Cain, taking on the mark comes with a great cost and burden.

Episodes

9.11 First Born

Knowing that Dean wants the First Blade to kill Abaddon, and after seeing him kill a number of demons, Cain decides that Dean is "worthy" of carrying the Mark in order to wield the blade. Cain transfers the mark to Dean, where it appears on his right forearm. Cain warns Dean that carrying the mark will come at a cost.

9.12 Sharp Teeth

Dean and Sam have parted ways, but meet up at a hospital when they both find out Garth has been hospitalised. While there, Dean tells Sam about getting the Mark of Cain.

9.13 The Purge

Dean tells Sam that his research hasn;t yueilded anymore information about the Mark of Cain.

Mark of Cain in Lore

In the Abrahmic religions it is said that after killing Abel, God cursed Cain, saying that he would be forever separated from his family and become a nomad. The mark of Cain was said to be placed on Cain by God so "Therefore whoever kills Cain, vengeance will be taken on him sevenfold, and the Lord appointed a sign for Cain, so that no one finding him would slay him." (Genesis 4-14)