Instead of the Emperor, I feel the Dream Guardian could have worked better. Especially if they were reworked somewhat.
The Guardian being another adventurer also in the same situation as us, with a tadpole in their head with the ceremorphosis process being halted by outside means.
If said Guardian presented a case AGAINST the use of Illithid powers and absorbing more tadpoles because they, like us, are in the mindset of preserving themselves and "Mind Flayers are bad, lets not be one" (They can be the one remarking that you lose part of yourself when you utilize illithid actions and such - This can also be highlighted in dialogues where the Guardan/companions ask about you but you stop being able to remember. Same thing with talking to illithidized companions)
Then we could have had some unknown force inside the Artifact (The "Daisy") that provided us, and the Guardian, with the halted ceremorphosis and being the voice that urges gaining the Illithid powers.
Who this unknown force ends up being, is debatable. Is it the Emperor? Is it the Elder Brain? Is it some magical Gith that just exudes an anti-ceremorphosis aura because reasons? Is it some "Absolute" character that is being exploited by the cult (Much like Aylin and Ketheric)?
I think that could have been easier to write a more solid story for.
Giving players that choice; do they follow the advice of the Guardian and try and find a way to deal with events without illithid powers to retain their self? Or do they embrace illithid powers and follow the source of their extended survival?
With the endings being something like, if remaining pure, the Guardian whom you've been siding with all game and presumably have grown attached to sacrifices themselves to save you to deal with the Netherbrain. While if you went the illithid route you had the power to save everyone else, but at the cost of your own self as you turn into a Mind Flayer.
Meanwhile, throughout the story you can have clashes between the Guardian and the Daisy. As well as the reveal of Daisy and responses to it (Do you fight them and make them submit to your will? Do you make a deal with them? Do you side with them?)
I feel that would have landed better than "Emperor, who is Balduran because of course he is, wants you to tadpole up because being a Mind Flayer is apparently the bestest thing ever. Meanwhile, the reason for the lack of ceremorphosis is magic Gith man Orpheus. But if you side with the person who's actually been saving you the entire game then Mind Flayer man gets mad and becomes evil because no-one likes Mind Flayers besides him"
yes, i think you hit the point.
i remember the first meeting with the dream guardian, he/she tells tav "i am just an adventurer, the same situation as you.".
we can see the origin setting that the dream guardian should be another "true soul".
this will make the story standfast.
but somehow they insert emperor in stead of the original dream guardian setting, just for his convenient background??