I Married a Stand-In Bride. After Our Divorce, She Regretted It and Turned Dark

[Lighthearted humor + marriage substitution and spouse pursuit + play the pig to eat the tiger + restoration of the kingdom and political intrigue + personal growth] An heir to the Keepers of Balance descends the mountain with a marriage contract, seeking the hand of a noble family's legitimate eldest daughter. He meets with rejection again and again, suffering one humiliating social disaster after another. Disheartened, he decides to give up. But the younger sister accidentally glimpses heaven's secrets and learns that the young man is the fated one destined to help her achieve great things. She immediately volunteers to take her sister's place in the marriage. After the wedding, the younger sister establishes herself independently and makes a name for herself, unaware that the Keepers of Balance are secretly supporting her all along. Seeing her husband idle away his days, she gradually grows resentful, deciding he cannot be the fated one, and resolutely asks for a divorce. On the day of their divorce, the full power of the Keepers of Balance is revealed. The younger sister finally understands, and her regret grows wild as she begins a long journey to win her husband back. But she is a descendant of the former dynasty, burdened with the mission of restoring it. Swept along by fate, she gradually turns dark and sides with a foreign country's Grand Wizard, intent on overthrowing the entire dynasty. At court, the princess and the crown prince contend for the throne, while a great general rebels with his army. Forces stir beneath the surface, and the realm is on the brink of chaos. After enduring countless ups and downs, the young man finally awakens to his mission as a Keeper of Balance: to set things right and restore the balance of heaven and earth. Once he has quelled the turmoil and earned renown across the land, the sisters who once abandoned him and the proud, noble princess are overcome with regret, all vying to win him back.