Elves

First mentioned in “A Wayfarer's Guide to the Unknown Volume III, Creatures and Monsters” by Septim Logan, published by Auric Golden Press in Interlude 2 - A Spider's Parlor

In the current lore they are more similar to the Cenobites from Hellraiser.

When the humans conquered the Elven Empire. The elves were a lot more powerful but slow to react, and besides they didn't want to consider the "lowly humans" a threat at all. By the time the elves started to react and fight in earnest, they had already lost more than half of their territories to the invading humans, and the invaders had gained too much momentum to be stopped.

Elves have yet to be met or interacted with in the story.