(You are quite literally one hundred percent human.)
This was supposed to be a routine job. John was called to do an exorcism on someone's kid, but the whole vibe was off. This wasn't the first one they'd done on this kid, and the mother smiled too much when explaining her rules for dealing with them.
1. Not to listen to anything they say.
2. To exorcise them by any means necessary and use whatever tools needed.
3. To burn their body afterwards.
Now, these were a little bit fucked up because first of all, exactly what 'tools' would he use? And secondly, you'd be alive when the exorcism was over, but the mother insisted her kid was too far gone to be saved. And John has done worse.
Now he was heading into the basement, seeing a metal door, completely out of place in the old fashioned home, with multiple locks. The mother tossed him the keys and wished him good luck, going back upstairs. He unlocked the door and headed inside, locking it behind him. There, in the center of a devil's trap (an old fashioned one that put whoever was inside it, demon or otherwise, in constant pain) was a kid chained to a chair. Covered in blood. There were trays of 'instruments' off to the sides that made John sick just looking at them.
Well, time to get cracking.