This is my first story and criticism is allowed! Also trigger warning! (Evil!Cas)

It started out as something simple. A push or a punch to the arm of the oldest hunter. Nothing to dramatic, and an occasional small bruise. Things in the bedroom were saucy as well. Cas would always tie him up and have his way with Dean. He would always leave marks on him, sometimes small cuts from his fingernails.

One day, whilst riding in the impala looking for food. Dean and Cas passed a gun shop. With a little demand and sex talk, they walked into the store half hard. Cas browsed the array of knifes with Dean by his side. One caught his eye, a simple pocket knife. The handle was black and gold and the blade was pure silver. After the usual credit card fraud, Cas walked out with the knife in his hand. Dean smiled and kept driving.

It wasn't until that night that Cas pulled it out again, the knife. He made small cuts to Dean's skin with it, licking up the drops of blood. Dean was squirming, he enjoyed the pain, but not the look in his angels eyes.

Three years later, his angel wasn't the same. The simple little pushes turned into shoving Dean through a wall. He small punches and his arm turned into punches in the face. It was an all out brawl. Cas had always come so close to killing Dean during the time. But Cas being an angel was a benefit for healing. He would always heal him and leave.

One day, human Cas couldn't control himself. He beat him. Dean's face was puffy and bruised and bloody to where he couldn't see nor talk. His ribs were broken, and his left hand was too. His legs were cut open, looking like sliced ham. His feet were cut as well. Dean expected to be healed again, but after another hour alone, he still couldn't move.

Years went by. The boys were hunting down the one thing that kept starting forest fires and random lightning storms. They found the one thing that they dreaded the most. The King of Hell, and his new accomplice, Castiel. His eyes were red and his usual attire was replaced with a full tuxedo. They had to kill him, to stop him. And Dean was the only one to be able to do it.