Creature Design Concepts
The initial concept behind these creatures was that they were supposed to look geometrical and made of stained glass, just like the realm they inhabit. Many shaped like humanoid figures, but some of human hands or heads. The things they were supposed to represent were suggested as being too specific, so I thought against it.
This was a more recent idea, a noodley humanoid with arms that can reach the ground with insect-like movement. On top of that, they could perhaps disguise themselves as normal people to manipulate others to do as they want.
You won't know who the character in that sketch is.