When Dean Winchester is attacked by a Djinn, Sam Winchester rescues him and reveals he has been back from Hell for a year and hunting with cousins Gwen Campbell, Christian, Mark Campbell and grandfather Samuel Campbell.
The Campbells go back to the house Dean is sharing with Lisa and Ben Braeden to catch the Djinn, but when they realize the Djinn are watching the house, Dean suggests they need to leave so the Djinn will attack. During the attack, Christian helps Samuel to trap the female Djinn, Brigitta, and loads her in their van.
Christian is at the compound with Samuel, Mark, and Gwen when Dean and Sam arrive with the baby shapeshifter. According to Samuel, Christian and his wife, Arlene, have been trying for a baby. Christian agrees to take in and raise the baby shapeshifter, over Dean's complaint that he "shouldn't be raising anything", but the Alpha Shapeshifter appears, overpowers them, and takes the baby back.
Dean doesn't entirely trust Samuel, but, when he tries to break into his office, Christian waylays him and they trade insults and threats. Christian attempts to discourage Dean from coming on the mission to get the Alpha Vampire by telling him that "accidents happen" but Dean ignores the threat, and it is on the mission that Dean sees Samuel, Sam, and Christian load the Alpha vampire into a van. Sam tells Dean that the Campbells have been capturing some creatures for the sake of interrogation, and Dean resolves to follow them to where Samuel is holding the Alpha. Dean and Sam manage to talk to the Alpha vampire but are eventually discovered, and Samuel, Christian, Gwen, and another hunter hold them at gunpoint and force them to disarm.
When the Alpha Vampire escapes, it snaps Christian's neck, but when it is distracted with Sam, Christian comes up behind it and injects it with dead man's blood. Christian's eyes are black, and several more demons show up and take the Alpha away with them, leaving just Dean, Sam, Samuel, Gwen, and Crowley. Crowley reveals that Christian has been possessed for a while and serving as his mole, and that Samuel has been working for him, gathering high-ranking creatures and trying to learn the location of Purgatory because Crowley is interested in "developing" it. How long Christian had been possessed for is uncertain as, earlier in the day, Castiel was in the same room as him and didn't mention anything.The demon now works at Crowley's side in a disused prison where they torture and interrogate all the creatures the Winchesters bring them for information on Purgatory. He encounters Meg, a demon still loyal to Lucifer, trespassing in a corridor and incapacitates her. "Christian" begins torturing her with Ruby's Knife, demanding to know "everything". She is unimpressed by his methods, stating that her vessel has seen worse treatment, to which "Christian" answers by escalating the torment. He gets nothing out of her, however; as Dean sneaks up behind him and takes the knife, stabbing "Christian" through the back, instantly killing him and the demon as Meg taunts him about Dean's presence.
- Christian is a full namesake of actor Christian Campbell, who portrayed James Frampton in the Season 8 episode "Man's Best Friend With Benefits".