Okay. I see where he is going with it. My prediction:
He wants Rangii to publicly step down and have the older sister take the throne.
Quite frankly, the older sister can be King herself. So the question is, Why has she not done so already?
With this backstory revealed, I get the feeling that the older sister is or has been using Rangii as a "Puppet King" of sorts.
Hence why she is so hellbent about ,the impressionable and easily manipulated, Rangii holding the King status.