We all got different sense of morality, so our level of tolerance will be different.
This has nothing to do with shiping and I actually don't see a lot of people focusing on romance in this thread.
Yes, I don't want him as ML because I find him unredeemable as ML. If he is simply a character used as plot device, then fine. But it would make no sense if the author tries to develop romantic relationship between the 2 later on. He literally put her through 7 years of mental anguish and hatred for him, it's kinda hard to flip that around.
I don't pity him because he didn't only kill Mir's parents but many innocent people. Civilians, noble families, his 5 Queen consorts.
Yes, he was betrayed. But he was the one going on a rampage, killing innocents and hurting God's favourite child, causing him to be cursed.
Him not being able to die despite being in pain and covered in injuries is his retribution for thinking that it was okay to make hundreds of people be responsible for 1 person's action. Even after becoming human, he continues killing.
So no, I personally don't sympathise with him.
And no, I don't think it's okay for him and his empress to manipulate Mir for their own gain.
Also, seeing what those two are willing to do and sacrifice to get what they want, I don't think they would make good rulers either. I can see them valuing their personal gains more than public's interests.
But you've got your opinion and I've got mine. Just don't assume that we all got shipping goggles on just because we dislike a character.