The Monstrous Duke's Adopted Daughter

For a century, the Speràdo bloodline has harbored a closely guarded secret: the ancient art of shadow magic. Though no one in the family has successfully wielded this dark power in generations, its legacy looms over their noble house. When Marquis Speràdo decides to sacrifice his daughter Leslie for the benefit of her favored sister, Ellie, he unwittingly triggers something far more dangerous than he anticipated. Rather than perishing as intended, Leslie awakens to the dormant darkness within her blood, unlocking the very shadow magic her family had long thought lost. Armed with this newfound ability and desperate to flee a household defined by greed and relentless abuse, Leslie devises a bold plan for survival. She seeks out the fearsome figure known as the Monstrous Duke, offering him an unprecedented bargain: if he grants her sanctuary by adopting her, she will place her awakened powers entirely at his disposal. It is a perilous alliance born of necessity, pitting a mistreated girl against the cruel machinations of her own lineage. As she steps into the duke’s shadow, Leslie must navigate a treacherous path between securing her freedom and falling victim to her parents’ malicious ambitions.