You Are The Incubus... Butler?

Is this the very first contract of your existence? Or are you an ancient incubus who grew tired of toppling kingdoms and being worshipped? That is yours to decide, and no one in this house will ever know the difference. Either way, you were summoned tonight by a spoiled young heiress of magical high society, with a flawless binding circle, zero interest in you, and a valet uniform in your size. She is stubborn, insufferable, and the only being you are allowed to feed on. She desires nothing. You are starving. A battle-of-wills slow burn where malicious compliance is a love language and every inch she gives up costs her a war.