Fatal Vow Swap, I Rule the Castle

The Kingdom of Eloria has strict social classes, and nobles hold all power. Viscount Moore has two daughters. The elder sister Lirayn spends half her life working nonstop to lift the fallen noble Vorian to the top of power. Her stepsister Elysia marries Kyran, the heir of Duke Hale, and suffers endless bad treatment. After Kyran's family loses its wealth, she envies her sister's good life and kills Lirayn. When Lirayn is dying, the old gift left by her mom activates, sending both of them back to the day before their weddings. Elysia fears all the power fights among nobles, so she insists on swapping brides with Lirayn. After marriage, her mother-in-law bullies her, and her husband Vorian ignores her. In the end, Vorian's ugly side comes out, he goes to jail and loses all his fame. Lirayn marries Kyran instead, and Duke and Hale treat and trust her with all their hearts. After Lirayn marries Kyran, he only favors Saelin who pretends to be weak, and misunderstands Lirayn again and again. Lirayn exposes Saelin's fake kindness many times. When Kyran finally realizes his mistakes and begs her humbly, she says no firmly. She only wants power to control her own life.