This is the ref for the males of Lucifer's species. So...Lucifer.

Dear god WHOSE IDEA WAS THIS. Oh, right....

They are not terribly large demons, really only about the size of a typical humanoid, though obviously the proportions are a bit warped due to their shape. But what they lack in size, they make up for in wicked intelligence and a sadistic nature that makes them feared even by their superior beings. They have a very militaristic society, with regulations on everything from food to breeding, a setup which leaves the males with a considerable advantage over their female counterparts, an advantage they exploit mercilessly.

Skilled warriors, they are feared for their vicious weaponry, specially crafted by their own smiths, never an outside source. The biggest thing to fear of them, however, is the fact they are near-impossible to kill unless you use one of their specially crafted weapons, or if you are a Xerta'axx yourself. No one is sure why this phenomenon exists, but it is a terrifying truth no matter what. Broken bones mend in moments, torn flesh knits back together before your very eyes, and a very angry demon will be lunging for you again, most likely to be the last thing you see.