The Emperor could just keep his mouth shut...

About the identity of the chained githyanki.

Who's that gith? Oh i don't know, found him here and found out he has special psychic ability, that's all. But no - he had to say that it is Orpheus in front of Bae'zel, so that she would be obsessed with the idea of freeing him. Emperor's downfall by the end of the game is the product of his own mistakes.