detegis

Detegis is a primary antagonist in the 2011 anime series Puella Magi Madoka Magica. The being is depicted as a massive, ethereal creature with immense magical power. Detegis are born from the grief and sorrow of Magical Girls who have died in combat, serving ascommentary on the costs of the magical empowerment such girls gain.

It is mentioned that Detegis were first created when Madoka Magica, with her Fated Death, became a Soul Ruby and broke free from the bonds of her own existence. This allowed her to create the first Detegis. The entity feeds on the negative emotions of Magical Girls who have perished in battle, gradually drawing power from their defeated bodies.

Magical Girls infected by Detegis eventually succumb to their corruption, becoming shadowy, powerless, and increasingly misshapen manifestations of what once were the girls. Puella Magi is contrasted with these demons, drawing the themes of existential cost and calamity.