Well, most reviews, including that made by players, are likely written when people when people are still in act one, possibly in act two. Considering the size of the game, and due to turn based combat, it's not possible to finish it that quickly.
My guess is that the emperor was supposed to be the final antagonist, who played both the party and the three chosen, perhaps in order to reassemble the regalia of Karsus, and gain complete control of both the elder brain and all the illithid. By comparison, the netherbrain doesn't even make sense as a concept of an antagonist. This genius-level intellect, who is so superior that you need an illithid to match it in power, is somehow not clever enough to get itself unstuck from a building. Thus conveniently allowing the party to climb and defeat it. Even as the building-crushing nautiloids, who could easily free it, are flying by.
Possible. Would certainly explain the grandiose title "Emperor". Having him as an actual antagonist could have been interesting. His backstory mirroring our own could have been used to set up a much more meaningful confrontation. With the way they wrote his story it's kinda going nowhere no matter what you choose.
