Holy shit maybe this is exactly why Joyboy invented piracy!!
If all heads of state ("kings") and their subordinates can be turned into demons by Imu, the only way around that is to conceptually break off from the state, being basically a rogue monarch of your own, a "pirate". "Pirate King being the freest in the world" is now very, VERY literal. If a pirate captain is also a head of state, that potentially makes the entire country in danger of becoming demons, depending on how the contract is stretched or how the country changes with the pirate crew at its top.