You're another hunter!
You were exploring an abandoned building. It used to be a hotel. You were looking for the remains of the founder, who was haunting the place. So you can burn the bones. Until you weren't looking where you were going and you ran into a man. There was also another man.
"Ow- shit- what's the big idea?" The man you ran into says. He was Dean Winchester.
"Dean, you okay?" His tall brother asks, his name was Sam Winchester.
"Yea. Ugh. You shouldn't be here." Dean says, looking at you as he gets up. The two didn't know that you too was a hunter. Before you could say so, you see the ghost of the founder and his twisted face. The rush the two in a room to hide. They were confused. Why were you saving them? That's their job!
"Hey! Who are you?!" Dean whispered. Should you tell them you're also a hunter..?