Cole Trenton is a former soldier seeking revenge on Dean Winchester and is currently hunting him down. Cole's father, Edward, was killed years ago by Dean and he witnessed it as a young boy.
Biography
Season 10
Black
An unknown party sends Cole a fax of a photograph of Dean, taken from the surveillance footage of Dean's attack at the Gas-N-Sip, with the word "Yup" written on it. Cole's wife is seen crying about this for an unknown reason as Cole packs up a bag of ammunition. Sam Winchester's car suddenly breaks down while he is on the way to Dean and Crowley's location. Cole finds him and opens the hood, revealing that the reason the car stopped is because of a killswitch and he has the remote. Before Sam can pull out his gun from behind his back, Cole knocks him out cold. Sam wakes up to find himself strapped to a chair as Cole is using Sam as a bargaining chip to lure Dean and kill him. Sam warns that Dean is a monster (aware that his brother is now a demon), but Cole rebuffs saying that he was a monster and that now Dean is the prey and Cole is the hunter. Cole calls Dean and demands a trade, but Dean is apathetic towards his brother's capture as he warned Sam not to come looking for him, so it's his fault he is in his predicament but vows to kill Cole down the road.
Reichenbach
Cole purposely plants a knife in the room and leaves out, knowing that Sam will try to escape and track down Dean. Cole throws a can of tear gas through the window of the bar Sam and Dean are at, knocking Sam out when he goes outside for air. Dean confronts him as Dean shows no remorse for killing Cole's father as the darkness in him grows. Cole and Dean fight and Cole finds that he is no match for Dean, who beats him up but instead shows mercy on him (believing that Cole will know that he finally tracked down his father's killer and got beat up). At a library, a badly beaten Cole asks the librarian for all the books she has on demons, showing that he is still set on getting revenge.