Originally Posted by SerenaNinf
I think it's not exactly true that he can't feel something. There are some lines in the game that make us realize that he may still have emotions.
First of all, some old lore books tell us that Mindflayers have emotions. In most cases they are negative emotions, but this is not always the case. There are exceptions, not many, but they do exist.
Some of the lines in the game suggest that the Emperor has some sort of feelings, and there's even a scene where you can feel his emotions yourself. I mean, it would be possible to develop something deeper from that, the lines are there, the choices are there, the only problem is, the consequences of these choices are not... And we are talking about a game where your choices matter.
If you don't mind, I will further delve into this with a reddit comment of mine:
The Emperor certainly behaves like a mind flayer, but thing is, there are numerous occurrences that hint at him being something deeper than just that, and those don't depend on him.

There are perception and insight skill checks that never lie and work regardless of what the Emperor - or anyone else for that matter - wants or thinks; those exist specifically to see through acts and facades. There's for example that dream sequence in Act 2 where you need to pass at least 2 (or was it 3?) different skill checks in a row in order to notice that the Guardian is in pain/frustrated (depending on which roll was successful, if any). We can choose to act on it or do nothing.

Then there are moments - small but all over the Acts - where the Guardian/Emperor reacts in weirdly human ways when there's absolutely nothing he can get out of it, and it doesn't seem like he's in control of those reactions to begin with. We first see those in form of the narrator telling us about his emotions flowing out of the artefact, like when we venture to the githyanki creche. Those emotions can be fabricated, I guess, but the thing is, the Guardian doesn't really say much, only maybe asks us not to go once and then falls completely silent. Another good example would be going to find Ansur, where the Emperor starts complaining seemingly out of nowhere, telling us that there's nothing to be found in there. His choice of words is very interesting, and it's kind of obvious he'd much prefer to be anywhere but near the dragon. Then there is his super defensive reaction if you call him a freak, his frustration if you go to the House of Hope and emerge with nothing (yeah, if you leave the hammer in the House, he'll be like "you've made better decisions than this" (= why did you even risk our lives going there))... plenty of those. Nothing to win, no useful information to learn.

Not a lot of people mention this, but he also has a really short temper, which delivers a number of funny scenes but only should we pick specific dialogue lines (like if we try to detect his thoughts when we see him in his true form for the first time, he goes, and I directly quote: "You must be joking. I am TELLING you my thoughts. Directly. Into. Your. Head.", or if you decide to crush the tadpole he gave you with your boot, he reacts with: "You absolute horror! (lmao) Do you know how hard it was to find that? To cultivate it to be safe for communion? Waste. Utter waste.").

There's plenty more of those things, not to mention the illithid prophecy and both the narrator and illithid Orpheus's lines, among which I honestly find it very difficult to believe the Emperor feels nothing/has no actual personality. But if he really does feel nothing in the end, and if his personality was fabricated in order to make him more appealing to us, I hope that the devs can at least implement a dialogue or two where the characters who romanced him can clearly realize that. It would be fair.