Re-Living My Life with a Boyfriend Who Doesn't Remember Me (Manga) Vol. 5

Oriana is going to the ball with Vincent! Though they're not going as a couple, Oriana is just happy she can remain by his side. All seems to be going well for everyone until an incident with Yana and Azraq occurs. Yana must marry whoever defeats Azraq in a duel, but because Azraq is so strong, no one can best him! Or at least, that's what everyone thought?