The chains of a broken promise (Izana Wistaria x Reader)

With the mysterious disappearance of Arthur, a new counselor was chosen for the young Empress of Utopia Avalon. With his arrive everything changed and now the Empire established in the middle of the ocean to start to socialize with the rest of the world; but with that the young Empress started to remember what she forgot time ago: a promise she made with the first prince of Clarines kingdom and the reason behind the strange curse over her.
Leaving her Kingdom in charge of Shin, her new counselor, she travel to Clarines in search of Izana to fulfill the promise she made with him but when (y/n) finally managed to see him, she discover that the prince have a new fiancé... What will she do now?