The Iblyn
(Say Iblis but [Ib-blin]
(In other words Sonic Worldbuilding lore)
There are multiple versions of these guys
In one universe (The Alternate version of Sonic X) they are aliens, whom are a part of an army called The Final Regiment
In a second universe they are supernatural transcendent nightmare beings who appear in people's dreams and sometimes in their waking moments. They are often described as dark, ethereal and wierd.
In another universe they are demonic alien like beings unlike The Black Arms. More savage but often described as savage as one can get, but have a certain poise about them as if all of them come from a royal bloodline. Act regal but are still dark and bloodthirsty. They wield magic, but some prefer their hands to fight and kill.
In another universe they are described as supernatural messengers. Again dark, ethereal, and wierd. Very ominous in their messeges. They do appear in monk like robes. Hooded figures.
In another universe they are a tragic species. Tortured and twisted beyond recognition, but not comprehension.