Fairy

Fairies are beings with souls who have a special things in their souls. Fairies can come in all different forms but all fairies have bug like wings. Fairies aren't a species and are instead people who have their souls corrupted in a certain way making fairies always prominent to evil. As such because being a fairy is a being with a corrupted soul, a person can become a fairy through enough corruption in their heart, in a similar way a person can stop being a fairy and turn back to whatever species they're supposed to be. However fairies have different levels of corruption and the higher their level of corruption, the harder it is for a fairy to turn back. Also it should be noted people becoming fairies are through their souls themselves and not through outside although it does help.

History
It is unknown what caused fairies to exist in the first place. According to legends to by the fairy kingdoms, fairies came from another world to spread magic into the universe. Some theories are far more sinister, saying fairies were beings created by the dragon or life forms whose soul has been affected by the dragon themselves.

Appearance
Fairies can come in all different shapes and sizes due to any race being able to turn into a fairy. As such there's no way to describe what a fairy would look like. However all fairies have bug like wings no matter what race the fairy is supposedly be.

Extend of the Fairies
Fairies live in multitude of different planets as it's possible for people to become fairies and vice versa. Fairies are universe wide although some places have a higher concentration of fairies than others which means fairy monarchies exist everywhere.