Ballad of the Vermilion Gate

Princess Yun Qi transmigrates as a discarded fake heir. She divorces her husband, steps on the real heir, trains her ex-husband general into a loyal dog, recruits the prime minister, and disciplines the richest man's eldest son. She relieves the famine with water carts, saves the epidemic with medicine, wins public support, becomes a county princess, saves the queen, and executes the concubine. Finally, she ascends the throne as the regent princess.