
I have a feeling that Xia Xu's family it ia or was a important clan of vampires, well I don't know if there is important clan of vampires in this manga

Betcha dollars to donuts that his mom was supposed to be the REAL legit heir to the throne (thus making Xia Xu the REAL Vampire prince and the current prince is a usurper/imposter or some such). And that the mom locked Xia Xu's abilities away, using the box, in an attempt to protect him by making people think he was a "faulty half-breed."
Yeeeees NianNian, yeeeeees babyyyyyyyyy but still sad he will end up with that bastard