he didn't spare Mia (previous timeline) even when the maid and Prince Able, himself, died trying to save her. You'd think that knock some senses into him to not kill Mia but nooooo for the love of justice, I must kill this girl. Prince Able even died right in front of the chamber (it might be outside the place she's lock in but I could had misremembered) Mia was hold in. If you think about it, Sion was truly the villain of Mia's story. Imagine a prince coming to save the princess only to be stroked down by the villain and even killed in front of the princesss. Tragic isn't it. The maid who willingly died trying to save Mia, must mean that the relationship between Mia and her people are at least decent, because the people were angry at Mia for not being able to help them when they're starving and hit with plague. The maid represented the people, and if the maid died trying to save Mia then that must mean her people avoided the plague and had food to eat. Prince Sion is just so deep into his lust for justice that he doesn't uses his brain to think about who the true culprit is for the harassment of the baroness girl (sorry, I can't remember her name), he believes everything at face value. Someone could lie to his face and he'll believe the first person who lied, so that's why he believe the lies that his spy told him about Mia. Even in the previous timeline when he saw the handkerchief, he auto assume Mia is involved. His dumba** doesn't think for a second and think that it could be a copy of the real handkerchief or that Mia is somehow clumsy and lost it and that she's framed?? A handkerchief in the scene of the crime doesn't prove anything, it was there but it doesn't mean Mia did it. Like cmon Sion, use your brain. Able isn't any better but at least he isn't a complete ahole and can be redeemed.