Brady

The Demon who possessed Sam's college friend, Brady, did so sometime during Spring break. The demon initially forcibly possessed Brady on his master, Azazel's, orders, yet soon he grew to bond with Brady, and Brady used his scheming nature to manipulate events into being the demon's friend.

Having bonded with the demon, Brady soon integrated their personalities so they were one being, and Brady pretended to a worried Sam he was just going through a "bad phase" of his life, akin to drugs. Unknowing that Sam knew about the supernatural and could have helped, Brady pretended to Sam it was a bad time in his life and Sam tried to cure him.

Brady now served Azazel, and did his master's commands. Perhaps his most evil act was slicing Jessica's stomach open, burning Jessica alive, and pinning her to the ceiling. Brady was a very sadistic, cruel demon, and took delight in his victim's pain.

Brady - the human Brady - did well at university and became a lawyer in a large corporation upon leaving university. Brady excelled thanks to the demon inside him and he charmed humans. He was in league with Crowley, and conspired - possibly in a romantic way - to bring about Lucifer's downfall. Crowley declared they were "Lovers against Lucifer" and Sam and Dean were sent by Crowley to get Brady from his offices. Dean kidnapped Brady, who was very charming to him. Sam recognized Brady when Brady was captured and bought to him, and Sam got really angry and upset and wanted to kill Brady or torture him for vengeance of what he'd done to Jessica, because Crowley hinted Brady had killed Jessica and not Azazel. However, it was on Azazel's orders, just because Jessica was "a distraction."

Azazel was dead, but Brady was still there, and Sam tortured him for why Brady had killed Jessica. Brady was giving them pleasure with getting them nowhere, until Hellhounds showed up. Brady got all cowardly at Hellhounds, and begged to get out of his bonds. Crowley disappeared, appearing to cowardly flee. But, Crowley reappeared a few minutes later, with his own Hellhound, having gone to Hell to get it. Then Crowley set his Hellhound against the others.

Crowley handed Brady over to the Winchesters, having no further use for him. Brady tormented Sam about how his addiction to Demon Blood was driving him into a monster, and Sam had had enough and killed Brady.