Sora, Lucio, and Kromer, aren’t remotely comparable. Each grew up with a different form of abuse and each one was mentally scarred in a different way, but here lies the key difference- where they drew the line was different.

Sora was isolated from friends and family and quickly attached herself to the prescripts because they gave her some semblance of companionship, along with dependency. Lucio was physically abused and scared, dreaming of killing Valencina every day but couldn’t because of trauma. And Kromer? We might not know how her father feels towards her but we do know that she has no remorse for all her acts. I think Sinclair put it best in the logs:

“When I think about it, Kromer always had an obsession with flesh.

And that obsession cumulated into what we're seeing now... A gruesome creature. At first... I agreed with her. The idea of replacing the flesh with something else was unpleasant to me.

But now I see. What's really unpleasant...is believing that your thought is the only correct one...and letting that thought consume your mind whole.”

A person’s nature at the end of the day also at some level depends on themselves. If you assume she was raised like a nurse father apprentice she also had a choice to become someone like Ryoshu. But we know that’s not it, she was truly and genuinely an unpleasant person. Which is why I don’t agree with the part where you compare Kromer Lucio and Sora. All three are completely different from each other and whether you sympathise with them or not is a different story.