Gadreel

Gadreel is a villain appearing in the ninth season of the television series Supernatural. He is played by Tahmoh Penikett and Jared Padalecki.

History
He first arrived, possing as an angel called Eziekel who was a friend of Castiel, and offered to help Sam, who was seriously damaged by the trials of hell. Dean reluctantly agreed, after checking with Castiel to see if Ezekiel was a good angel or not. After his attempts to heal Sam fail due to the ammount of damage, he offers a chance to heal him by possessing Sam, and lying dormant. Reluctant, but seeing no other option, Dean agrees. Gladreel vists Sam in his mind, and pretending to be Dean, tricks Sam into giving his consent. Gadreel stays in Sam, for several stories, occasionally manefesting to talk to Dean and help if he needs it.

In "Holy Terror," Gadreel informs Dean that Sam is almost fully healed. Later, Metatron confronts him and reveals his true identity: Gadreel. In the past, Gadreel was the protector of the Garden of Eden but failed his duty by allowing Lucifer into the garden, his evil corrupted the Garden; for this, God imprisoned Gadreel in Heaven. Metatron offers Gladreel a chance to reform and join him and be a hero. Gadreel agrees and joins Metatrons side. Metatron however tasks Gadreel to prove he is loyal enough. As part of the task Gadreel murders Kevin and leaves the Bunker with the angel and demon tablets.

Later he kills another Angel his former guard. Going to Metatron, Metatron gives him his next assignment, to kill another Angel. Gadreel is orginally reluctant, but goes along, till he finds the angel is his former friend. It turns out the angel has taken the body of an abusive husband, and adopted his family and life as his own making everyone happier, seeing it as his second chance. Talking to Gadreel he convinces him to go after what he wants and let nothing stop him, regaurdless of the price, unaware of Gadreels motives. Excepting this Gadreel murders him. However he is confronted by Dean, he defeats Dean, but is overpowered by Cas. Taking him to Crowley they try torturing him to access Sam, so Sam can take back his consent and throw Gadreel out. However this fails (although they do learn Gadreels true identity), so Dean is forced to trust Crowley to possess Sam, so he can reach Sam. Crowley suceeds, but is confronted by Gadreel, somewhat out of character, the demon fights, but is quickly overpowered by the angel. However Sam Gadreel back and revoking his consent kicks Gadreel out of his body. Gadreel then travels to his former vessel, who once again gives him his consent, and Gadreel possess him again.