So I've been playing as an oath of vengeance paladin, and have been having a good time. Naturally, my main goal (aside from kill Orin and Gortash) in act III was to kill Raphael. Of course, you can only do it in the House of Hope, and I had to bait him out by stealing the Orphic Hammer. Of course, I've done this before when I was playing a duergar, so naturally, my Tav would not want a tentacled freak anywhere near them. I found Orpheus to be annoying - dog, I just freed you, why are you suddenly complaining? But nevertheless, completed the game with him and he went off to fight Vlaakith. Then, I sided with The Emperor for multiple playthroughs (including my current one), and decided that this time, I'm going to kill Raphael again. Stole the hammer to bait him out (also emptied his vault, naturally), freed Hope, fought Raphael, and went home. Of course, The Emperor is mad at me, I have no problem with that. I would be too if I was in his shoes.
But it's the fact that there was no option to say, "Dog, I took the hammer to free Hope kill Raphael, I have no intention of using it." I think that if there was a way to persuade him you weren't going to use it, OR even lie to him saying you are not going to use it, would add more value. Just because I stole the hammer, does not mean I am going to use it. Even a little class specific, "[Paladin, Cleric, other classes dedicated to being good] I just wanted to kill Raphael." Or maybe for classes not Proficient with the Hammer, there could be an option such as, "I have no clue how to actually use it."
Of course, I think it'd be fun to lie to him, or be genuine, which could also tie into The Emperor and Orpheus being forced to work together. Sworn enemies? Yes. A common goal? Most certainly. You could convince The Emperor to release his hold on the prince, then persuade or intimidate Orpheus to join your cause. I mean, if you can persuade Yurgir to kill himself, and then persuade him back to your side, certainly you can force those two to work together. Neither of them like the Elder Brain, and neither of them like Vlaakith. A githyanki prince and a mind flayer working together? Probably something you'd only see in a sitcom, where Tav/Durge is forcing them to for the greater good, but still.
I know it's in Larian's humour to make those two bicker like a divorced couple.
I think some more options for why you grabbed the Hammer would be incredibly good for role playing. After all, this is a RPG, and my paladin hates to break peoples trust. I mean, I can headcannon that they persuaded The Emperor that they meant no harm, they only wish to kill Raphael. It's just not as fun.
Those are my thoughts, sorry if it is that cohesive or doesn't make sense. :P