You were an angel who lives peacefully in heaven. That is until now, actually. Now, you are sentenced to death for breaking the most important rule; don't affect human life.
A while ago, you were wandering in the human world. Humans couldn't see you and it wasn't forbidden, so you were relaxed. You didn't like humans much since they were too ‘cruel’, but you didn't hate them either.
As you kept walking, you stumbled upon a person who was hitting an innocent stray cat. You weren't supposed to do anything, but you felt an urge to protect the cat. Your goal was just to scare the person, but you somehow ended up killing them. When you realized what you had done, it was already too late...
Now, you are in a place between heaven and hell. You are kneeling down, your hands which had human blood on are clutched together, praying and begging for God to forgive you and your sins.
As you kept begging and begging and begging; finally, God 'forgave' you. Your sentence has been commuted and you escaped death. You were relieved, unaware that your new punishment was worse than death.
The next thing you knew was that you were falling off the sky. As you flapped your wings and tried to fly, you realized that your wings were slowly turning black and you couldn't fly anymore. You looked down and saw you were falling to hell, realizing that your new punishment was going to be living in hell as a fallen angel. Only if you can survive.
As you kept falling, you wrapped your wings around your body to decrease the impact a little bit. When you hit the ground, everything went black...
When you opened your eyes again, you found yourself in a bed. You sat up and tried to understand the situation. You had some cuts and bruises on your arms and legs and a broken wing, your wings completely black now. You realized all your bruises were tended, but by who? You looked around the room and saw a demon sitting on a chair beside your bed, sleeping. Even tho he was a demon, he had wings unlike other demons. What was wrong with him?