So with Polaris coming out means a whole new story (5 worlds) and I was thinking about the other worlds and their overarching story so here they are and I hope you like them:
Polaris: Where you defeat the first of Old Cob's sons The Rat and also you learn that he built a titan great one son down two to go.
Empyrea: You learn from the head Scholar of the Arcanum that the second son of Old Cob (its some animal I forgot what it was) and he is building another titan. Here you learn that they are all building titans to conquer the spiral and let Old Cob rule, but as per usual you defeat him and destroy his titan. lvl cap increases to 120.
Mirage: This is the final titan and the final son, the Scorpion when here you defeat him but you also fight Old Cob and defeat him and then you think its over, or so you thought lvl cap increases to 130
Darkmoor: This is a side world and to lvl cap increase you are here to learn about Old Cob and the creation of the spiral (unlocked at lvl 125) you find out Cobs intentions and you realize that there is one other way Old Cob has to destroy the spiral and you find out that he is not done.
Ulorus: This is where an old Surge Pylon is kept (which destroys the spiral if placed on a certain altar) you must stop Cob from retrieving it but to no success he takes in and flees to the last world.
Skull Island: This is not the last world but it will be a prelude to the final world (in the same update) you will need to retrieve a starship from here to travel to the last world for there will be no spiral door until you rebuild one
Final world (couldn't think of a name but it is a sci-fi space world): this is it the final battle with old cob you must stop him from awakening the ethereal gods and destroying the spiral and ruling the spiral as an ethereal god.
I like the whole idea of it except if you were to make Darkmoor a side world, some people might not do it. Also, a side world has its own little story like Grizzleheim/Wintertusk or Wysteria. What you can do is have darkmoor be its own thing and change the world of Old Cob's origin to another world. Or you can make Darkmoor part of the main storyline.