Also i just like seeing hot fictional men begging (*´∀`)♪
Before the curse, he was already someone who was willing to kill others for his gain, fabricate lies and manipulate, and just twist other people's lives with no regards for them. The curse didn't make him poison Crocetta. That's a choice he would have made to keep someone by his side, curse or not. And I think that's the point of the story. You have three men who are affected by a curse, but what they do with that comes down to who they fundamentally are as individuals. Etienne was someone who only cared about his wants and needs. Arnold was someone who struggled with sympathizing with others but still had some softness on the inside. And Roger was a righteous person.
I don't personally feel bad for Etienne. His childhood may be bad but that doesn't justify the adult he chose to become. Having bad experiences during childhood may contribute to what you decide to do with your life. But ultimately, your actions are solely yours to control. Someone else with the same childhood wouldn't have chosen to become such a shitty person.
They're all very well-written characters
Bruhhhhh I hate Etienne so much but at the same time I feel pity for him with the way he's begging. No matter how sick and twisted he behaves and how much I dislike him at the moment, he's still a victim to the curse. Also, I think as the crown prince, the trauma he endured as a child, especially seeing that panel where he got poisoned as a child (really tugged at my hearts strings) I cant help but feel bad for him because he wanted to be loved and the curse just made it 100× worse and turned it into an obsession. I really like him as a character because he's such an evil bastard and you hate him but also you feel bad for him because of the circumstances that made him an evil bastard lol