The Domineering Villainous Prince Pursues His Wife

1v1, both pure. Two strong leads, a satisfying power fantasy. A cold, glamorous modern-day assassin transmigrates into the body of the timid, cowardly eldest daughter of the Nan family, a useless girl. When she wakes, she remembers how the original owner met her end. Nan Manqing? The Regent's Consort? Hmph, fine. Since I'm here, I'll take on the original owner's grievances for her. From now on, anyone who bullies me had better be ready to face the consequences. A deranged villainous Regent, a bloodthirsty demon king. A coup to seize the throne? Toying with the heroine, then fiercely pursuing her in a fiery, desperate bid to win her back? The main story starts out infuriating, then turns sweet and doting. The supporting characters get both angst and sweetness.