Tefrosis

A condition developed by those who regularly interact with the magical energies and spirits of fire.

Over time, it causes the flesh of the body (usually the tips of the extremities first, then traveling towards the torso) to blacken and shrink towards the bones, resulting in a skeletal appearance.

Paired with the glow caused by the presence of high elemental energies within a body, the appearance is often described as looking similar to the remains of logs within a fire as it burns down to the embers.