Mangnaniui Nunimisida

After losing her father, bratty brother, and the Elias Empire to her traitorous fiancé's schemes, Princess Legina makes a wish upon a magic ancestral stone and returns to when she was 15. With one last chance to right everything, she comes up with a plan: train her spoiled sibling to be the next ruler by becoming an even bigger brat and get Aaron Vestein, the most beautiful man in the empire, to replace her fiancé! But will just wits, resolve, and a new suitor be enough to change Legina's fate?

(Source: Tapas)

Note: Includes 10 extra chapters.