Finally finished this one! This is Tiria. She is part of an ancient tribe who lived in the darkest parts of the Twilight Realm. The tribe is characterized by dark, grey and black skin and hair with "empty" eyes. They have lots of bioluminescent markings and often wear darker clothing to blend with the shadows. They only use their markings to easily find each other, and their body shapes are somewhat hidden to predators, making it hard to get caught.

More lore about my concept below:

The Twilight Realm has different levels of "shadow" (since apparently darkness is different than shadow in the TP universe, let's just refer to it as shadow). At the very bottom of the Twilight Realm, you have the darkest parts and there is a surface. It is dangerous to live here, as natural monsters and predators are far more common than they are in lighter areas. Demise's influence is strong here, even if it is in another dimension.

Twili who once lived there were known as the ancient Zenath (might change that name later, but for now it sounds good). They were among the first twili after the Interlopers. They possessed strong shadow magic, thanks to the Interlopers' previous efforts. However, their powers do not come without a cost. Eventually, the Zenath lost their minds in search of even greater power. Thus, they became an example of why present twili do not search further than what they are naturally capable of.