It's a bummer that all the other solutions except "become a mindflayer" are more or less a hoax. The set up for that solution isn't even well promoted and instead is just thown at the player in the very end. Sure, the Emperor keeps telling us that it would greatly help our cause if we turned, but still. Not having any other options feels like everything else was just a red herring and didn't matter. I wanted to outsmart this brain! I would have wanted to see alternative routes leading to the final battle:
1. Become a mindflayer, so you get enough powers to resist the brain. I have no idea how this is supposed to work, since the brain's story IS to control mindflayers, but apparently this is their main story arch, so sure.
From what I've understood from others, this storyline could simply be about another form of mindflayer - I'm not familiar with the lore, but apparently there is a type that's independent. This path could unlock if you take too many or enough tadpoles (however you see it), and the Emperor could try to persuade you to take this route.
2. Get rid of the tadpole before the final battle by making a deal with someone, eg. Raphael, some other devil, or a god, or Orpheus.
Then characters wouldn't have to worry about the brain taking over them anymore, and maybe they could get an additional storyline to free themselves from the contract (fullfilling it or outsmarting their way out of it). Eventually they'd still face the brain, because they can't have it roam free and take over the worlds.
Regardless of the path, I'd then want to see the option of what they actually do with the brain:
1. Destroy it
2. 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).
3. Rule it yourself or with your companions
Maybe you'd have a little power-struggle with your companions, if you've played their storyline to the point where they are power-hungry.
4. (accidentally) Give the rule over to the entity that you made the tabpole deal with
Maybe have the power-struggle with them, like you would with Gortash/Orin.
