Jailor wants to escape his ancient banishment in the Maw, he has been manipulating people for eons, you must locate allies and collect stuff, while trying to stop him escaping (hint, you won’t because that would end the story abruptly) and reshaping reality (this may not happen in real time, mortal)… Clearer now.
Also if that is all a problem, consider this:
Change Zovaal for N’Zoth, and the storyline becomes remarkably similar…the major difference being, that you had heard of the Old Gods before, so it didn’t frighten the horses, because lore…except you have to write lore at some point which means at that point it is going to be new.
No-one turned around to Tolkein and said:
This Sauron bloke, how come we have never heard about him before you wrote this book called Lord of the Rings.
Why are you retconning The Necromancer in Mirkwood, from the Hobbit, that’s canon that is… and why are you palming us off with someone who is not the real big bad.
We have to read an enormous book and there is never a fight with Morgoth, who is Sauron’s boss… ‘Lord of Waiting for Morgoth’, more like!..this is clearly a cash grab while you write the next book.
Also why do you keep mentioning people we know almost nothing about, are they going to be in ‘Morgoth First Class’ …maybe we need a Palantir, or some other Gem to understand the storyline better… Well yeah, there is some stuff about them in the Appendices…but of course we have to buy the Epic Three Volume Edition, for that…shameless greed from the author. I shall be reading CS Lewis in future.