Good at first, but not so much later.
Remind me of The Lord Empire, MC got so horny that it gets fuking annoying.
Such a great concept, ruined by MC lower head.
Like it at first, but got dissapointed later.
Just use one world as the main, use the others as an addition. I don't even know what do you want to write in the latter part.
Good starting point, but got bad later.
I don't mind adding all kind of new stories to a fan fiction, but at least adhere to the original setting of the book.
Why people always love adding mythology and God to all kind of fanfic?