Oh my godddd uhhh I mean right now when i'm painting The King of Yamimakai in my off-time (You heard it here first folks!) the answer is kind of set in stone. He HAS a single reference card in "Contract with the Yamimakai" and I always assumed that despite not being enormously powerful himself he's like the head of some minor netherworld faction/fiefdom.... I think an archetype predicated on court politics within "The Kingdom of Yamimakai" would be cool.... A whole array of "Second/Third/Fourth" Princes of Yamimakai etc., "Vizier of Yamimakai", "Palace Guard of Yamimakai" etc. It's close to Dark World thematically but more about internal conflict over the throne.... mechanisms that involve like summoning two competing Princes of Yamimakai who come with built-in effects that Ritual Summon one of several possible Kings depending on which one dies first (Either to tribute, ritual cards that simulate being assassinated or crowned etc.). The idea would be that the deck can build to a handful of different possible boss endboards based on what you want it to respond to.... one Prince becomes a King that has fantastic battle phase interaction for countering a battle phase heavy deck like a Tenpai, one Prince has counter trap stuff or can out floodgates, one Prince enables mass summoning of synchro or xyz fodder because he has the loyalty of his men etc. I like the idea of a deck that's mostly "responsive" to other decks in a given format but only if it can make concrete choices and resolve the inner "power struggle". Play would be about preserving the combo route to the specific KIng you want... or learning how to make do with the one you could make it to, and the whole thing is full of unsettling classically Takahashi-esque sofubi/post Mcfarlane monster morphology.