Idea #43 (Hades(the game)/Kingdom Building)

The concept is that after they have escaped the Underworld multiple times, saved Persephone, and essentially they finish the whole story, Zagreus becomes the king of the Underworld to give his father, Hades a much needed break. He realizes that everything that Hades has done has been organized in a certain fashion for eons and it isn't working as well as it could because the amenities in the Underworld are still from ancient Greece. This is sets the foundation for a kingdom building fiction to make the Underworld an actually prosperous place, even though it must complete its original goal with the souls of the dead.