Fallen Reaper

A bright lush fantasy world where magic and monsters rule, and for any other universe, someone has to control life and death. Without it, society and nature would collapse. The player is the Grim Reaper themselves had a routine day snatching souls from the damned and letting the people who have no time left rest in peace. But while taking a soul from a great mage, they suddenly felt a sharp pain which would be impossible for Death. They felt their life force and power drain from their hand, limiting their power. They fell from the ground and into somewhere unfamiliar. They notice their body feeling unfamiliar, too human. Realizing they fell from their glory from the grim Reaper to a mere mortal. Not ultimately human, they could still consume souls. But at this form they have to consume thousands. They don't know how it happened but they knew it had to do with the great mage.