Chris

I can't believe that you say that the Emperor "is just a good guy in general". He is flat out evil. There is nothing redeeming about him whatsoever. He is the reason you're in this mess. He constantly is trying to corrupt you and turn you more and more into a mind-flayer. He lies to you over and over. And if you free Orpheus, he joins the Netherbrain in a fit of spite.

Orpheus, on the other hand, actually "is just a good guy in general". He just wants what is best for his people. And, not so coincidentally, what is best for his people, happens to be the best for everyone. He wants this so much that he is willing to sacrifice himself for the greater good. I followed his example. I freed him and became a mind-flayer myself, because his people needed him.