Hong Tianshen Zun
Summary
Xu Nian is the most powerful genius in history, but was abandoned because of family suppression. After experiencing the revenge of the family, the goddess of the realm was admitted into the harem, the deity of the demon world bowed his head as an apprentice, and the dragon of the demon world was a mount! Annoying Xu Nian, whoever touches Xu Nian’s reverse scale, will definitely die better than life! Adapted from Xu Sanjia’s novel of the same name “Hong Tian Shen Zun”
In a system like that there would need to be rigorous documentation and certificates of prior ownership/guardianship or else anyone and everyone would just get grabbed off the street and enslaved at any time, and such a society would collapse instantly. So these slavers wouldn't have such documentation unless it was a forgery since the kids were just kidnapped; both offenses should be very serious capitol crimes. Once again, the day is saved by glorious Bureaucracy! (and the MC's knowledge and exploitation there of).