All your actions have real-world consequences. People can revolt against you any time, and there are several governments in exile that might be wanting their autonomy back. The only super-natural part of this hypothetical is that you spontaneously seized power overnight.
Immediately use my new-found power to restore the sovereignty of every nation, with the exception of Belgium. I want 20 million dollars from them first, and if they refuse I'll split their tiny nation between the French and the Dutch.
Chance are I'll get my $20 million, and live longer and happier than anyone else would in that situation.
Use that power to establish democracy around the world, and step down right after that
If my experience with Crusader Kings II applies, I would probably just fuck my cousin.