My Contract Beast Is an Infinite-Evolving Mosquito

Reborn as a lowly mosquito, Sean Crew receives a system prompt: to evolve, he must drink blood. During the Beast-Bonding Ceremony of the campus belle, Lucy Gough, he instinctively stings her. Unbeknownst, Lucy is the reborn empress who once ruled the realms, and her blood triggers an ancient bond, turning Sean into Lucy's Bound Beast.