(( Okay so
Among other things, I was thinking - is there a court system, or are all decisions made by the king?
It would explain who decides when Jokers switch sides. Maybe they switch sides when the Jacks don’t do their job properly?
What happened when Gilbert was the only Joker? Who controlled him? Was he on his own free will? Was he originally associated with a certain nation? How did Ludwig become King while Gilbert was the Joker? Why did he switch sides? Was it the courts’ decision to trade, or the kings’?
Are the tails attached to the clothes, actual devil tails that mark them as the Joker, or something else?
Are normal citizens aware of the Jokers? Who would be considered a normal citizen? Do all numbered nations live in the (castle)? Is there a castle? What time period could this be compared to?
What kind of technology exists? How do people travel? How often to representatives from each nation meet? How do they communicate? When do they fight? How is news spread? What weapons do they use? Are there horses? What kind of magic, if any, exists?
Am I going too deep into this ))