Gunner Lawless was a wrestler whom Dean Winchester was a fan.
Season 11 Edit
Gunner was a wrestler who sold his soul to a crossroads demon named Duke so he could win a championship title. Ten years later, Duke approaches him offering to call off the hellhounds if he kills people on his list.
Gunner is reluctant, but chooses to do as he's told and kills one person in every town he has a wrestling match at. Among the wrestlers killed is Shawn Harley, who Gunner initially wanted to spare since he was "just a kid".
When Sam and Dean infiltrate Duke's hideout, Duke orders Gunner to attack Dean. Gunner proceeds to tie Dean up, and is surprised the man knows what Duke is: a demon. Gunner explains his deal with Duke to Dean who tries to convince Gunner to do the right thing. Gunner ultimately agrees and releases Dean who draws Duke's attention. While Duke is focused on Dean, Gunner kills the demon from behind with the demon-killing knife. With Duke dead, nothing holds back the hellhounds any longer who come for Gunner. Though the Winchesters offer to help him, Gunner returns the knife to them and stays to embrace his fate, believing he deserves Hell for what he's done.