Since losing two characters is arguably better than the entire party becoming mind flayers, it’s likely preferable to choose the Emperor’s side and not free Prince Orpheus in Baldur’s Gate 3.

Should you let the Emperor assimilate Orpheus?

To summarize, players should side with the Emperor if they don’t want to become Mind Flayers , and they should free Orpheus if they don’t mind all the tentacles.

Is it better to side with Orpheus or the Emperor?

If you romanced him prior to your choice, this may complicate things further. But siding with the Emperor won’t be popular with all your allies – namely Lae’zel if you didn’t turn her against Vlaakith. Any romance with Lae’zel will be broken by choosing to side with the Emperor and failing a DC30 Persuasion roll.