Come up with ATL royal styles in place of Your Majesty, Your Highness, Your Grace etc.
Go!
Go!
On two ends of the spectrum;
H. Most Celestial Majesty
and
H. Most Infernal and Maleficent Majesty
I don't figure many would want to use the latter, but yeah.
IIRC, polish and other languages get their word for "king" from Charlemagne (according to... google translate it's król in polish)
Perhaps the same fad spreads to other languages?
A more military minded king could go for something like "King Commander" perhaps.
Hm that I think would work best for a German state if for no other reason than it sounds better in German (König-Kommandeur/Königkommandeur) than anything else.
Like how the German and Russian words for Emperor came from Caesar?