Cinderthief

A Cinderthief is one of the fundamental forces of the 'spark' magic in the universe, caused when too many sparks soak into an area be it over eons or hours. They collapse together akin to a black hole, consuming all manner of spark-corrupted non-living matter in and scrubbing it of sparks, and if the local concentration gets too low wandering towards the highest concentration of sparks it can sense, including other cinderthieves which is one of the few ways found to reliably stop them.

The purrification process is not perfect, with the material consumed as part of it burning to fine powdery ash and clinging to the spindly frame of the cinderthief and eventually 'growing' into the hardened chunks along their spine, which also inhibits the process further causing more and more of a 'cloud' of sparks unable to get consumed and floating around their shoulders chaotically.

The 'face' is different for every person that views one, with those too young to have learned to lie reporting seeing nothing at all, and some claim it can be communicated with but not with words or any audible noise.