In Baldur's Gate 3, one of the most crucial decisions awaits players near the game's climax: freeing the imprisoned Githyanki Prince Orpheus or allowing the Emperor to handle the situation. This choice, made after acquiring the Orphic Hammer, significantly impacts the party's fate.

Updated February 29, 2024: Before this pivotal decision, players must defeat Ketheric Throm, Lord Enver Gortash, and Orin, requiring exploration of Baldur's Gate's upper and lower districts. This final battle against the Netherbrain may also lead to companion sacrifices. High skill checks (30+) might be needed to influence companion choices.
(Spoilers Ahead!)
Should You Free Orpheus?

The choice hinges on player preference. The Emperor warns that releasing Orpheus risks party members becoming Illithids (Mind Flayers). After the Netherbrain encounter (within the Astral Prism), the choice is presented: free Orpheus or let the Emperor absorb his power.
Siding with the Emperor: This leads to Orpheus' demise as the Emperor absorbs his knowledge. Lae'zel and Karlach may disapprove, impacting their personal quests. While this ensures victory over the Netherbrain, it might not please fans of these companions.
Freeing Orpheus: This causes the Emperor to potentially align with the Netherbrain. The risk of party members becoming Mind Flayers remains. However, Orpheus joins the fight, and if asked, will willingly sacrifice himself to save his people.
In short: Choose the Emperor to avoid becoming a Mind Flayer; choose Orpheus if you're willing to risk Illithid transformation for your companions. The Emperor's choice might alienate Lae'zel and send Karlach back to Avernus.
The Moral High Ground?
This depends on individual player morality, but boils down to loyalty. Orpheus, as a Githyanki heir, opposes Vlaakith's tyranny. A Githyanki player might naturally side with him. However, following Voss and Lae'zel's directives might seem overly demanding to others. The Gith prioritize their own kind, even if their actions affect the wider world.
The Emperor, conversely, aims to stop the Netherbrain and aid the party. He acknowledges necessary sacrifices. Choosing him might lead to Illithid transformation, but ensures a morally upright (if tentacled) victory. Remember, BG3 offers multiple endings, allowing for outcomes that satisfy various moral compasses.