or the meta knowledge that it was placed there to be the player's reward for eeeeeeevil.
I think it’s important to note The Prism doesn’t exactly grant its powers to anyone willy-nilly? It seemed that way at first, but it's a sentient being and even you had to convince it to free Minsc. It’s definitely something to consider when someone talks of wanting to free Minthara using its help. Overall, I’m actually content with how it is in game and would just prefer a route where she can choose to live for another day without having to mass murder people first.
You don't ask for its help with any origin companions and Nere, tho? You needed to make Empy do as you want with Minsc, not Prism/Orpheus. If you show Prism to Jaheira in Act 2 - it makes her tadpole in jar pop. So yes, it works passively petty much.
Empy doesn't take over until we take out these gith monk guards.