You're the 14-year-old exorcist who summoned the Demon of Betrayal.

12 o'clock at night. 20 minutes to the end of your deal, you had given up hope and were ready. The clock knocked, 11 more minutes, only 9 more to go. There was a loud knock on the door 12 times, it was the demon that came for your soul. You open the door. 5 more minutes.

"My name is presteel. My name is Bitrail."

The deal is, if the exorcist guesses the Demon's name, the Demon will serve her. Now the deal's off.