Board Thread:Theories and Speculation/@comment-28939725-20180103103451/@comment-34674418-20180212145744

Here is the reason on why Kinshiki considers Momoshiki a "lord";

Due to the law of consistency, adult Otsutsukis sees the younger ones as royalty. The reason behind that Is because Otsutsuki kids carry the legacy of their ancestors. The young ones are the culmination of the continues evolution of their clan.

There is another reason why Momoshiki is "so special" to his father (to the point he allows himself to be converted into chakra fruit ).