I might have an unpopular opinion about this, but I actually like the change from Daisy to Guardian. Don't get me wrong, Daisy was a nice trope for seduction to your darkest desires, but... I don't want every character in the game to seduce my Tav, so this feels like fresh take(I know that we can
romance the Emperor, but that is on us not on him!
). Then again I totally agree that how that change and how that plotline was executed is really inconsequential and should be revised because as it is now, it contradicts itself unfortunately.
I gave my take on this and Omeluum on the thread in suggestion&feedback section of forum so I will just copy my post from there:
+1, totally love this scenario here and would go for this in-game if I could, much more reasonable than what we've got. I personally don't understand why we're so railroaded with some of the characters. Like... the Emperor and Astarion(at the beggining of the game) are mirrors to each other, survivors!(and mind you there are other situations like that in game...) If you understood Astarion's character and gave him a chance and the Emperor cleary saw this... if You've met Omeluum and was friendly with him, and yet again the Emperor must have know about this... Why would he not give you at least a chance to explain yourself, appeal to his reasoning? Especially if You somewhat bonded with him! Why not promise You that he will let Orpheus go after all of this(and indeed make him the evil one if he would eat the prince behind Your back, that would at least give us a real and serious reason for wanting to kill him and a cool plot twist for scheming character)? I see him going to the Netherbrain as a desperate attempt to preserve himself, but only when all other choices would have been outed and how is it handled now shows he doesn't even believe in Tav's and companions abilities to preserve themselves which contradicts precisely all of his mighty plan to build up trust with them and use them for it. Why using things that You know wouldn't work?

And Omeluum... I greatly dissapprove how he was used in the story. Cleary his only purpose was for us to see that there can be somewhat good aligned mindflayer and to give us some boon(which have a lot worse meaning storywise and mechanicaly in full realese of the game). That just it. Meeting him don't have any meaning for the Tav and companions, they don't even have a serious talk about this; there is not even "oh, the Emperor is mindflayer, we know another one we could ask for advice in this matter" talk. The narration unreasonably takes from player a choice for Omeluum to be an ally in the end of game in which one of most vital points is freedom from Elder Brain for a mindflayer! You give player a character that have a power to get himself out of control of Elder Brain, capable of self sacrifice and think nobody would think about asking him for help in the matter when he cleary also is in danger along with all the Sword Coast if the Netherbrain plan comes to life? It's a huge overlook in various ways for me.