Kai Winn is a great character and it is all about her flaws. Dukat is an utter sociopath which is surely a huge flaw and he is an epic character.
I think people admire the flaws of villains but you have tread carefully with the flaws of heroes.
Was he? Dukat treated Kira's mother quite wel.
He enslaved her world, oppressed her people, and forced her to become his personal concubine. And, no, it's not "treating her well" if he has the legal right to rape her, which he did.
It's like Chris Rock talking about the relationship between Sally Hemmings and Thomas Jefferson. "People are calling it an 'affair.' 'Thomas Jefferson had an affair
with Sally Hemmings.' Bullshit. It's not an affair
if you can't say no. The word for that is 'rape.' "