Basic Structure

Module One
Overworld

The Under

Nether

Hellish Amphitheatre

Spelunker's Expanse

Magmatic Expanse

Shallow End

Ghast Domain

True End

Deep End

Potenta Pyros/Lekta/Cryos/Aeros/Decay/Hemosphere

Stellax

Ether Nexus

Deeper End

Module Two
Just Apocalypses, expand later

Module Three
Hall of Heroes

Module Four
Great Council