I think the biggest problem with the Character of The Emperor lies within how freeing Orpheus is handled.

As i understand, the various interactions you have with him differ in regards to what information he gives to the player, depending on wether you are trustful of him or if you are dismissve or outright hostile to him, like calling him a monster. But there is no reactivity to any of this in the finale. When compared to most of the games major decisions and dialogues, that there is no way to try to persuade The Emperor, especially when there is mutual trust in one anothers intentions, is going against one of the core elements of the game, that YOUR choices matter. I should be able to remind him of my reactions to reveals such as Ansurs death by Baldurans hands, of him dominating Belmane and (most likely) causing her strokes, him lying to you, not sharing vital information. If you, despite all that, then still actively support him in his plan, why cant he fathom the idea that he should put his trust into me?

It is even more baffling how binary this whole sequence is, when considering the prominent use of "Dialogue-Boss-Fights", especially in Act 2. I was honestly expecting for there to be half a dozen skill checks, covering various skills and saves, displaying a kind of psychic struggle between your conjoined minds. The Emperor would have been the perfect opportunity for one last major Dialogue-Boss that culminates in him trusting your judgement, ultimately saving Orpheus and all of your Companions, since someone apparantly has to become a Mindflayer, aswell as The Emperor. And if you fail, or if you were never in a relation of trust to begin with, he doesnt believe you can convince Orpheus to spare him, so the only possible means of survival is joining the Netherbrain.

I was really torn by this character and some related story decisions, but in general I do like The Emperor. I just think that the conclusion is a giant missed opportunity, given all that that they have done in regards to reactivity and decision making prior to this.