Players have been able to go to Hell due to the Hell Gate that was conjured up. Players could also change their race to Devils if they succeed in a mission in Hell. The ones that made the Hell Gate appear has already changed their race to Devils and has a good reputation in Hell.
The players that did not want to become normal humans anymore has already changed their race to Devil. The devil race has an incredible affinity towards Dark Attribute magic, and they could also have another secondary magic talent. They are definitely the reverse of angels as their overall appearance and aura are different.
Angels have pure skin that glows when light reaches it which makes them glow as if they are gems. Devils, on the other hand, became incredibly alluring as they get a perfect shade of shadows when they are in a dark area. Angels have wings like that of a dove or whiter in color while devils have wings like that of a bat with shades of red to black.
Updated.