I haven't really seen a ton of endings for the game, but from what I've read, thus far the Orpheus one appears to be the weakest and most unbelievable. I also remember being rather disappointed in it because I saved Orpheus with the idea that he would work with my PCs to defeat the Absolute perhaps without someone transforming into a mind flayer. I mean, here's this super powerful gith prince who the entire game has built up as a guy with incredible powers that can even defeat an elder brain's powers, but without any persuasion whatsoever, he just gives in and says, "Yep. The Emperor's right. The only way to stop the Absolute is to have someone become a mind flayer. No other options. Guess one of us is doomed."