Other solutions2. Rule it with Gortash and/or Orin
I haven't tried out what actually happens if you try to have a deal with Gortash/Orin. I've just expected them to backstab you and that you aren't allowed to take this path. However, I think you should be allowed to make this deal. To make it more interesting, I'd want to see some (political) power-struggle between them and the player before they settle in the new status quo, and that they'd still have to do something to get the brain fully in control (maybe the battle, maybe something else entirely).
On Gortash and Orin's deals in Act 3:
Orin clearly states that taking her deal means she will still attempt to kill you. I think she says she'll call off her assassins and wait to "duel" for Bhaal's favor.
Gortash, surprisingly, makes a good ally and holds up his end of the deal completely if you side with him! He joins you for the first confrontation with the Nether Brain. Then immediately gets his head exploded in the cutscene where you fail to dominate it.
I really loved the
beginning of Act 3, where all these different factions were vying for who would ultimately control the Crown of Karsus. It's really a shame it comes down to Dialogue Option 1 or Dialogue Option 2.
