The Incubus King

Story
Though the ostensible main villain, the Incubus King seems likely to play a smaller role in the plot. Though he holds one of the biggest Shards, he's not necessarily the most powerful person with one. He's definitely not one of the most competent, since he's dangerously stupid and ruled by impulse.

His arrival on Arclent (from Thenours?) completely changed the continent, setting off the war and destroying multiple nations. Since then, he's grown complacent and mostly sits in his lava castle. It seems like he leaves most of the management of his empire to Iris and inspires very little loyalty in anyone not in his direct presence.

So far he's displayed several fetishes that are on the odd side, even for succubi. These include the "crownjob" and something that involved a giant chess set made of feces.