If putting the tadpoles into your brain, with all it's possible negative side-effects, isn't addressed really early in game through a npc/book/cinematic, this is a horrible decision. Just from the ui look alone, with it's black tendrils covering your brain, it feels like this will have big ramifications and the incentive to go "bad" with these extreme good bonus abilities is massive. The vast vast majority of players will have ONE play through not multiple to see different outcomes of bad/good/neutral play-styles. This might ruin the games overall experience for a lot of players if there isn't a counter incentive for the tadpoles in your brain or a huge red letter warning. Furthermore an dialogue option 30 minutes before the games ending to make it all undone and just remove the brainmaggots without any consequences would be the worst path this could take.
I am sad that we have to tell people that putting additional illithid tadpoles in your brain is probably a bad idea. Then again we have instructions on packs of toothpicks.
I would choose to see this as an option for people who choose "power at any cost" - this is pure Lord Voldemort and Horcruxes. You gain power at the expense of yourself.
Remember, Astarion WANTS the tadpole but wants to control it because it "frees" him to some extent. So this is related to that.
What is incredible is that this is likely just a tiny part of the game that incorporates a path you can go down and its supports how much you want to descend into iniquity and self destruction.
Bravo!
