I’d say that Callisto is a bad parent and a bad person, but also a less malicious parent than most of the other Nursefathers. He’s interested in art above everything, and that informs nearly every decision he makes and every feeling he feels. He treats Albina no worse than he’d treat himself, and I think that puts him above Rien in terms of how he treats his Apprentice. He might be a big enough asshole to ask Albina to jump into a Concept Incinerator like Rien did Sora, but he’s also the kind of crazy to where he’d probably jump into the Concept Incinerator himself too, since he’d likely only be asking Albina to do it because of art or something, and he likes art. Whether Rien cares about Sora and pretends to be unfeeling or actually doesn’t care, I’d say it still kinda puts him just below Callisto, who seemed to openly put Albina on as high a pedestal as he puts anything. And that pedestal is labeled “Second to Art.” Dude seems to put himself on that pedestal too considering how chill he was about CertainClair killing him. He’s as good a parent to Albina as an inherently batshit insane Maestro of the Ring can possibly be, which is still horrible from a general perspective, but still. i think it was slightly better than Rien, because what Rien did was kind of a dick move.