FanHarem
.... I remember reading a doujin where the mc put a SEAL (Kai cando the same) on his bâlls lol... He could nut, but it was inert/infertile. The seal also strengthens the soldiers in his seed and the children born from it would be stronger the longer he has the seal applied. It also gave his nuts a barrier to protect them when he was fighting females onis.... You know, the usual lol