Sunlight as judgement. Fire at dawn.

Porphyrins absorb fiercely in the Soret band, around 400 to 420 nanometres — the violet edge of visible light and the near-ultraviolet. In congenital erythropoietic porphyria, a baseline human disease of haem biosynthesis, that absorption produces blistering, fluid-filled vesicles, red-fluorescing teeth and urine, and progressive dermal tightening. The haemophage runs the same photochemistry at industrial scale. Excess porphyrin, already excreted as cutaneous oil, sits in the skin as a film of photosensitiser.

Photons in the Soret band raise those molecules to excited states that dump energy into adjacent tissue as heat and reactive oxygen. The film ignites in the clinical sense: rapid photothermal and photodynamic destruction of dermis and subcutis. It is not moral. It is not a curse on the damned. It is a waste product catching light. Shade, cloth, and night are engineering controls.