My inspiration basically started with Vellioth's title "the Martinet", which is a synonym for disciplinarian, but specifically with a military implication. (In fact I just looked this up, it's named after Jean Martinet "one of the first great drill masters of modern times".)
So of course, with such a lack of other information, I'm gonna take that idea and run with it. The military, both historically and in modern times, is such a great source of evil BDSM yaoi torture scenarios. Have you heard of running the gauntlet? Blood wings? Blanket party? Keelhauling? Okay, the last one you can only do on a ship, but my point stands. If that's what army superiors do to normal people, imagine what an insane military sadist would do to another vampire.
It's no secret that Cazador is more lenient than his predecessor (1 year buried vs. 11 years impaled) so I think him seeing his spawn as his children is another form of his comparative "softness". Vellioth probably didn't see him as family at all, just a subordinate, more object than person. Cazador inherited his need for discipline, his sense of hierarchy, and his love of violence, but instead of making more subordinates, he tried to make a family. He's so tenderhearted! ❤️
Of course, this ties in with the Szarr family massacre in a nice way too... it's very very ancient warfare tactics for the victors to take the defeated as slaves. And Cazador rebuilding his family back afterwards from the ashes of Vellioth's defeat... how cute! Familial love perseveres.