The Demon Inside of Me (Grillby X Reader)

A long time ago, monsters and humans lived peacefully. Then, war broke out.

The monsters were forced underground, and the humans were left above.

A killing machine was created, to destroy all the monsters in the underground.

This is her story.

Asgore is the prince, who lives in the palace with his father (Nazur) - who is on the edge of death - and his wife (Toriel) and son, Asriel. Toriel and Asgore are about 20. Gaster and Grillby are buddies around 19. Sans and Papyrus have no set age, they're experiments. If they did, they would be 17 or 18.
Reader-chan is 18.