I have an hc that Behemo made a big mistake when creating Levia and Rahab, by making Levia what his parents wanted him to be like, while making Rahab how he wished his parents were, and thus, making them just as incompatible as he and his parents were.
For this, let's say Behemo created both Levia and Rahab, and had some control over both their personalities and backstories/life paths. Kinda like in The Sims.
Now. It's a pretty popular belief in the fandom (from what I've seen) that Behemo's parents in the First Period were strict and disapproved of him wearing dresses and taking interest in more "feminine" things, like playing with dolls. I believe the same, because if a maid, who, even though she was Behemo's girlfriend, was considered below him in social status, could call him disgusting without being scared of, like, losing her job or something, we could say that transphobia and general hatred towards people who didn't conform with gender norms was pretty par for the course in the First Period. And also, since gender norms were super big, a lot of focus would be on women being homemakers, people who should stay home and care for children and stay loyal to their husband, this kind of stuff.
Going beyond that, Behemo's parents could've also been those parents who valued academic performance to an excessive level. And if Behemo ever went below their expectations, they would criticize him and say how he should do better, stuff like that.
Then, when creating Levia, who was meant to be his "ideal self", Behemo chose to make her a genius. A prodigy, who would always excel academically and who was everything his parents wanted him to be: Smart, conforming (tho Levia is more tomboyish, she *does* oppose Behemo's crossdressing), and mostly focused only on her research. That was what his parents wanted, what he had internalized he should be like.
Meanwhile, when creating Rahab, Behemo was thinking of what *his* ideal parent would be like. Not how *Levia's* ideal parent would be. We know he and Levia are very different, personality-wise, so the ideal parent to Levia wouldn't be the same to the ideal parent to Behemo. Besides, we don't know how old he was when he created Levia as his avatar. For all we know, he could've been a teenager who wanted to have a parent who would be super chill with partying and stuff like that. An ideal parent to Behemo would be someone like Rahab, but the ideal parent to Levia would be someone very different.
And, if we take into account how he could've been a teenager who made Rahab based on how most outgoing teens, who have the "typical highschool experience" of being invited to parties and stuff (can you tell I did not have this experience lmao), would want their parents to be, I also imagine that he eventually outgrew that, and began to see his ideal parent as something different. Maybe still "chill" like Rahab, but not exactly a party animal with so many lovers that she didn't even know who her daughter's father was.
And that's why Levia and Rahab were fundamentally incompatible. And why, later, Behemo came to agree with Levia about how Rahab wasn't a good parent.
Again, this is just a headcanon and I'm pretty sure I'm making no sense, lol
This is my first time making an analysis like this, and English isn't my first language, so this might've been bad, but thanks for reading anyway :3
