Responses
Prob nothing he can do, regarding the imprisonment, since its already decided,and as to why yulan was quiet regarding everything was prob because MC was so determined on getting the prince's attention and hurting her sister since she was so jealous,she couldn't see anything else besides her goal,and yulan was just standing in the sidelines doing nothing,as he knows full well that MC doesn't even think of him

technically, Vio is not faultless since she did try to kill Maryjun, especially since Maryjun is actually innocent in all of this. But i feel like it was a little too much of her to do that based on the personality she portrayed, so there might be someone in the background. Also, where was Yulan when all the things in the past were going on, seeing how he cares so much(most likely loves) for Vio, it's strange he wasn't there for the imprisonment.