I Abandoned My Engagement Because My Sister is a Tragic Heroine, but Somehow I Became Entangled with a Righteous Prince (Light Novel) Vol. 3

Leia and Eric happily announce their engagement and begin planning their wedding, but naysayers have no qualms about raining on their parade. Meanwhile, an intruder breaks into the palace! Determined to prove her worth, Leia successfully chases down the culprit--and it's Lingsha's brother, Liu! Between her shock and Liu's disorienting magic, he manages to slip away... only to show up again at a diplomatic meeting between Elshaid and the Ren Empire! But as Leia and Eric try to question him about the break-in, he drops a bomb that shocks them all: the real reason the Ren Empire is here is to convince Eric to marry Lingsha!