
Yeah he was poisoned, but he still treat Ji Eun nicely right, that means he still has control over his own mind and action. That poison did make him go crazy but for him to abuse Tia only, it was because of the hates he has against Tia. Hatred that rooted deep within him form believing in HEARSAY, so that still would make him an ASSHOLE.

Zena and Ji Eun were working together the biggest thing that Ruve lacked was love and Duke Zena basically told Ji Eun that in order to survive and not get killed and r*pped was to should Prince Ruve love. Think about all the factors being put into play here. 1. A prince that craves love 2. A duke that wants power 3. A girl that's from a different world and only wants to survive. Ji Eun only got closed to the prince because she wanted to survive and the reason why Ruve treated Ji Eun so well was because she showed him "love" unlike Tia who at the time couldn't even express basic emotions. The poison literally enhanced the hate that he had for Tia. The Duke fed prince Ruve lies about Tia when he was younger and not to mention how the emporer dotes on her. So the Prince is a victim he didn't do all that hateful shit to Tia freely. Even when it was time to execute her he voted to keep her alive sp she could live quietly in the country side.
Guys I read a spoiler
Prince Ruve was actually poisoned by Duke Zena (that old crusty ass man) and he fed Prince Ruve lies about Tia. So the prince shouldn't be blamed for his actions since he was under the influence of a poison. Allen is also a sick person that you shouldn't ship Tia with (he has a wet dream about strangling her to death so she could be his) I never shipped them anyways because he rubbed me off tye wrong way. But There's a lot of stuff that's going to pop off in this
P.s. Allen starts to work with Duke Zena and even thought of killing Tia's dad (which is a big no in my book) I know everyone hates the Prince but it's not his fault that he was impressionable enough to be fed lies. The emperor barely shows him any love and that's what he always wanted and the duke used that to his advantage. The Prince was also poisoned so to add on to all the terrible things that was said he was easily manipulated to hurt Tia. From R*pping her and k*lling their child. The real victim here is Tia but the Prince is also a VICTIM