Third Person's POV
'Fiends' was the name given to the corrupted beings who were no different from other monsters and desired to consume living flesh or corrupt other beings in order to increase their population.
There are two causes for that.
Dark Mana was the primary and major cause of corruption. If non-habitants, except the Fallen people, tried to enter the Fallen Continent, the first thing that would transpire was their soul crystal immediately getting corrupted. Soon after, their body would follow suit, and finally, their sane mind.
What remained was a grotesque monster, driven by a singular goal of survival through the consumption of other creatures, be the monsters or fellow humans, along with their tainted soul crystals.
While these Fiends were initially weaker, their insatiable appetite drove them to evolve. It was less of an evolution and more of a regression to their original state before the corruption set in.
