Welcome to the Underworld, enjoy your stay.

Originally the Underworld in this webcomic was one whole landmass with multiple kingdoms, but it was retconned to, as a lovely anon from the first thread put it, Disgaea tier worldbuilding bullshit. A similar comparision is Kingdom Hearts, with the Underworld now being multiple worlds/realms with proverbial walls between them.

>>151115737
In universe lore page about the sectors of the underworld.

Here's the structure of this fic's underworld I guess

Apparently the real Danny Phantom's stuck in the Ghost Zone or some shit