It would have honestly been a lot better if the Absolute were to turn out to just be a pseudo-deity existing solely from the belief of the cult's hivemind, with the actual prayers and power going right to the Dead Three (whose involvement couldn't have been less subtly foreshadowed from the start, what with the constant references to the Time of Troubles and Jergal and the emphasis on the three Chosen). Get rid of the Emperor too, bringing Daisy back as the manifestation of one's corruption not by the tadpole itself, but by the Netherese shadow magic powering it and used to keep the cult together (and Shar's opposition to them, mostly ignored in the plot as it is now, would make more sense as they are effectively stealing from her power source), and of the Crown (because what makes a great plot if not an arbitrary MacGuffin?).
The Netherbrain honestly rivals the main antagonist of Pathfinder: Kingmaker in terms of pettiness and proneness to tantrums. Plus, the intro implies that the illithids are going out of their way to expose themselves on account of dying out, and yet that isn't reflected in the actual story in any way.
