The “strong personality” wasn’t an explanation as to why he’s different. It was The Emperor lying to Gortash and not telling him that
Ansur saved him from the Elderbrain.
If this is true, then this is just another reason why I wish they'd let us discuss these things with the character a bit more (I guess if the Emperor did ever state this directly, it must have been down other dialogue paths. I did generally choose friendly options, but I go down every single one). I'm totally onboard with the idea that this was part of the reason, but if so, I would have liked more acknowledgment of that.
As for the reasons of why he’s different, I think a lot of times when people are analyzing a story or character they assume every minute detail must have an explanation, when unless it’s story breaking, it’s not that important. He’s different because he’s different, and who he was before turning seems to have had something to do with that, but the exact details don’t really matter. Likely, as far as story telling, having The Emperor have this legendary past is more satisfying as to why he’s different than him being just some adventurer. Omeluum is also different and we’re short on details for him as well.
Omeluum talks about breaking free from his colony through arcane magic,
but the minutia of how he did that doesn’t matter. He broke free, and he’s another example that not all illithids are the same.
While I generally agree that not everything needs to be drilled down to the tiniest details, I think "Why are they different?" deserves at least a bit more attention. The player character is being presented with choices about using illithid powers, and ultimately about becoming illithid. Knowing why the Emperor and Omeluum are the way they area informs us about our own character's likely fate, and thus is a factor to be weighed when making that decision (and notably, Omeluum does not identify as its previous form; it's just free from the elder brain's control, which I think is a more straightforward situation). The game sort of gets around this by having the Emperor prepare a special tadpole for us, which means we didn't have a typical transformation, either, but having more buildup about how and why he did that would welcome. For example, it seems like he might be interested in having more mindflayers *like him,* free from the control of elder brains, possibly as suggested in the Adversary idea above. He does clearly think he's an improvement over his old self, but he never really talks about the desire to make more people like him outside of thinking it'd improve the odds of defeating the Absolute. If this is an ongoing project of his, I'd like to know more about it. Not even from a "'give me a scientific dissertation on this"' perspective, but just more about what it means to him and for our character. I don't consider this aspect to be story-breaking if it's not there, but it seems like yet another place where I had questions that seemed reasonable to ask but really couldn't be addressed. Frankly, if I weren't already familiar with the idea of how arcane magic interacts with the illithid colonies, I probably would have wanted to ask more about that, too.
