The Deedrn, aka the Third Caste, count as the third group of beings along side The Arkn and The Dekn. Being the only beings created in secret by the Hethe. Because of this, there are only four active Deedrn, three of which initially were meant for much greater purposes, which has since been abandoned.
Indroi Faccilis was the first Deedrn, and is the most controllable, but least successful. Indroi was created as the first of what was meant to be a government for the Arkn, but never deployed as the caste was never perfected. Working more along the lines of torment, and agony, Indroi never fulfilled its purpose and was abandoned rather than terminated.
Warin Hac Ysim
Warin Hac Ysim is considered the second Deedrn, and the most uncontrollable. Originally purposed to be the first of the Questions, another caste never formed, Warin Hac Ysim failed to meet its mark when Fab'ras created it to follow orders, because of this, Warin is sealed away in a tiny red box, made of flesh from one of every physical being in existence.
Harl Octa Wavc
Harl Octa Wavc is the third Deedrn, however it is the most reclusive and next to nothing is known about it.
Damerith Ist Eisz
The only known description related to the fourth and final Deedrn, Damerith Ist Eisz , calls it "The living Lord of dying Death". As of May 15th, 2016, DIE has taken hold over the Infernous and corrupted it into an inescapable hellhole of nightmares and monsters.