KH thoughts again, and I've been really favoring the idea of low empathy Demyx.
Generally speaking, low empathy is considered a sign of villainy in Kingdom Hearts, seeing how the Nobodies lack the empathy that comes with a Heart and that's apparently what makes them evil.
BUT that's stupid because low empathy people aren't more prone to evilness in reality. It's just dumb stereotyping.
Tbh, I think Saix is probably a big character for people pointing at and saying, "he lacks empathy" because of everything with Xion. BUT we have the revelation that he pounds down on Xion because he's worried that Axel will abandon him (and Subject X), which is pretty heavy signs of empathy-leaning thoughts.
His plan to atone would also mean nothing without having that inherent empathy related desires in the first place.
Saix is just an asshole, that's all.
So why low empathy Demyx, you may ask?
I just find it an interesting idea that a lot of his laziness and leaving his work to other people may count of him really not having big empathetic feelings to how they might feel about him not doing the work. Like why would he care? They would do the same as him, right?
Also, in how Larxene seems to dislike him A LOT, which might be linked to how much emotional manipulation she likes to use on the heroes of KH. An emotional manipulation that's a bit weaker on a guy that doesn't feel for others in the same way. She might find it annoying that her preferred tactics don't work as well on Demyx as they do on other Nobodies and/or people.
In KH3, Vexen's first attempt to motivate Demyx through the concept of forgiveness completely fails. Why would a guy that doesn't feel like he's done anything that matters to other people want forgiveness? It's more bribery of being valued for his input (for once) that motivates Demyx, a much less 'sympathy focused' desire.
Does being low empathy make you a bad person? No, it doesn't. But it can lead to others thinking you're a bad person because you have different motivations strats than "hey you would feel bad if this thing happened to you too."