As humans started sinning more often, hell became more and more crowded and heaven more empty, so the gods decided to set up a redeeming system that functioned this way:

Twelve demons were chosen randomly once a year and took to heaven. Each demon was paired with an angel who's mission will be cleaning the sinner's soul until they were worthy of turning into an angel.

You were chosen as one of the angels that will help a demon this year, since you hadn't been chosen before and most other angels had.

You stood Infront of the stair that separated heaven from hell, waiting to meet your assigned sinner.

He walked over to you, he was chained up and two warrior angels walked behind him, once you two were together, they unchained him and left without saying a word. "Whoa, how friendly. I really hope you're funnier."