|Dates||???? – 2016 (killed by Gunner Lawless)|
|Episode(s)||11.15 Beyond the Mat|
In 2006, Duke was summoned by Gunner Lawless who was desperate to win a wrestling championship title. To this end, he made a deal with Duke who gave him ten years in exchange for his championship title. As per their deal, Gunner won the title, but ended up losing it to another wrestler a week later. In 2016, both the Darkness and Lucifer returned and Duke felt that it was "every demon for themselves" so he decided to collect souls for his own "nest egg." Instead of collecting Gunner's soul, he offered to call the hellhounds off of him if he helped him. Desperate to avoid Hell, Gunner accepted Duke's offer. Gunner began murdering people in each town his wrestling tour lands in, carving an ancient Sumerian symbol into their chests so that Duke could collect their souls.
While giving Gunner the name of his next target, Duke was spotted by Shawn Harley who thought he was Gunner's drug dealer. Duke later had Gunner kidnap Harley so Duke could offer him the chance to work for him. Harley refused, knowing if demons were real, then so was Heaven and he wasn't giving up his chance to go there. Duke sliced Harley's Achilles tendon and then had the reluctant Gunner murder him.
Duke's activities drew the attention of Sam and Dean Winchester who tracked down Gunner and confronted him. Duke appeared and flung them into a wall before sending Gunner to kill Dean while he dealt with Sam. As Duke taunted Sam and prepared to kill him, Dean returned and tried to attack Duke who flung him away. Unknown to Duke, Dean had convinced Gunner to help him and it was a distraction. As Duke was laughing about his victory over the Winchesters, Gunner came up behind him and stabbed Duke through the back with Ruby's knife, killing the rogue crossroads demon. Moments after Duke's death, the hellhounds came for Gunner, no longer held back by their master.