While I get that adherence to the established lore is definitely preferred, I'm not sure if that really prevents Larian from telling a compelling story with their modified version.
I do wish there was a little more acknowledgement of how atypical this is for illithids, rather than the Emperor sometimes acting like he speaks as a normal example of their kind. And I'd like a bit more justification than his "strong personality" -- did it have to do with being rescued? The attempted treatments he was given? Precautions taken before transformation? He was a renowned adventurer, after all -- if he tells me that some previous magical protections, skills, etc. that he'd developed contributed to this, I don't think I'd be too bothered by that; especially if teaching this to the player was part of how he ensured that they would also "survive" the transformation.
Mainly, I just wanted to see a more interesting arc or storyline from interacting with this character, even if it deviates from the D&D lore.
