Sounds like Assassins have more rules than we do. We kill things at any cost, but we're not supposed to be what we hunt. Not that that's ever made a difference in this family. I've been a demon, Sam's been soulless, Cas has just straight up committed genocide against his own people. In the long run it doesn't matter much. I can forgive everyone but myself.
I miss that job-well-done feeling. Last time I had it, I was borderline demonic. I killed a kid. Some dorky teenager who belonged to a family full of crazy. He wanted to run after I killed his father and his brothers, get out of the life like Sam did, and I thought, nah, there's something broken in you just like there is in us, because that's how shit like this works. I shot him in the head. I actually felt accomplished. I haven't felt good about my job in... I don't know. Years.