Cole Trenton

Cole Trenton is a recurring antagonist on Supernatural and is a lifelong enemy of Dean Winchester.

Origins
In 2003, Cole was awoken by a fight from downstairs. Heading down, he saw his father Edward lying dead on the floor with his throat slit. Cole saw Dean leave the house, and although he didn't know it, his father was a monster and Dean had killed him. Cole just saw the brutal murder of his father, and since then he began to hate Dean with a passion that evolved into a homicidal hatred for Dean.

Biography
Cole was in the Army and he toured Darfur and Iraq, seeing the brutalities of war such as child soldiers, and suicide bombers. Cole believed in the worst of humanity, and that humans were all damned. Cole sought to avenge his father, who he still believed innocent. He kept an arms locker in his house, full of machine guns and other weapons, but he did not have simple weapons like salt or Holy Water, because he did not know or did not believe in the supernatural.

One day, Cole set off to hunt Dean. At this time, Dean was a Demon, but Cole did not know it. He began sending Sam Winchester threatening messages saying Dean will get what's coming to him. Cole was warned by Sam that Dean was not human, but Cole said too bad. He then hunted Dean down only to be overpowered by Dean's supernatural strength when he found out too late Sam had been telling the truth.

Weakened, Cole retreated, headed to a library, and requested all the books they had on Demons. Cole was now better prepared, and he headed off to some of his old friends. Jemma, an accomplice of his, called him to warn him of her friend Kit's odd behaviour. Kit had been with Rick, her friend, and went to rescue one of Cole's fellow soldiers from Iraq but he was actually infected with the Khan Worm and attacked people. He unknowingly affected Kit, who got infected with the Worm in turn. So, Cole went to see Kit, but she infected him with the Khan Worm, and Cole tried to kill Dean with the Khan Worm's strength, but he got subdued and Dean fried the Khan Worm out of Cole.

Then, Cole had his final confrontation with Dean, where he said that his father, Edward, was actually an unknown monster. It was a monster that fed on human livers. It was unlike anything Dean had seen before. So, Dean knew Edward killed living people and he killed Edward after a fight. Knowing Cole was no monster, Dean let him live. Dean said that if Cole still desired vengeance he could now kill Dean because Dean was damned anyway. (Dean was no longer a demon at this point.) But Dean said Cole had a family and he could otherwise go back, forgive Dean, and live again. Cole chose the latter. Cole did put down his gun and he eventually thanked Dean for saving him from the Khan Worm and he went back to his family.