Demon Possession

Demon Possession (デモンポゼッション) is a Japanese manga written and illustrated by Ao Inku. It was serialized in the monthly shonen magazine Comic Dengeki Daoh and was later compiled into two volumes.

Predator

 * Grigori

Prey

 * Touno

Scenario
In chapter 10 of the series, Touno battles the Grigori, an entity that resembles a female angel. During the battle, the Grigori stabs Touno with its tail. In response, Touno unleashes a devastating attack that seems to defeat the Grigori. Just as Touno is about to deliver the finishing blow, she falls to her knees. She finds she is unable to move her body due to a paralyzing poison that had entered her body when she was stabbed earlier. Completely helpless, Touno can only watch as the Grigori opens its mouth incredibly wide, preparing to devour her. The Grigori engulfs Touno and swallows her whole, absorbing her power in the process.

Touno is not seen again and, presumably, died upon being digested by the Grigori's stomach acids, however that could be possibly debunked due to the fact there was still a large bulge the moment it indicating even if it did have a digestive system, Touno likely died along with it at the same time and not particularly by digestion itself.