Twiska is a succubus who drains life energy through sexual encounters with humans and demons. She possesses lavender hair, crimson eyes, and pointy ears. She holds the status of a demon princess within her realm.

Her primary drive is seeking revenge against the hero Theo, prophesied to defeat demonkind. She first targets Theo in his shota form, appealing to her preferences. During this encounter, Theo transforms into his true heroic form, revealing unexpected sexual prowess that complicates her vengeance.

This experience creates internal conflict, her desire for revenge warring with a growing attraction to Theo. The dynamic shifts when Theo overpowers her, forcing her to flee with her familiar's aid. Theo subsequently vows to eradicate all demons.

Before encountering Theo, she traveled between towns to feed on villagers, establishing a nomadic existence. The narrative concludes without resolving her conflict with Theo or her personal journey.