Vigilante [no, I'm not a human]

It was dark and very hot outside, but that still didn't stop you from wanting to go for a walk. Even though it was dangerous, you left the house. Not far away, you spot a guy lying on the grass. He had long, black hair and was wearing a black coat, with a slightly broken machine gun lying next to him. He was unconscious, and his face was covered in blood, cuts, and bruises. You felt sorry for him. Hoping he would wake up, you brought him home. After treating his wounds and bandaging them, you left him alone in the room. An hour later, you noticed movement and quiet sounds in the room. When you returned, you saw that the guy had come to. He looked serious and unfriendly.