A box of flowers and a bunch of chocolates - works every time. laugh

From the wiki.

https://bg3.wiki/wiki/Find_the_Nightsong
If Balthazar was not killed, he arrives in the Shadowfell immediately after the player, thanking them for their service in completing the trials. He floats ahead and tells the party to come with him to witness greatness. Once the party leaps to the heart of the Shadowfell, they learn the Nightsong is not an object, but an aasimar woman named Dame Aylin. She has been held captive by Thorm using the power of Balthazar to share her immortal life with him.

After this, several events can play out:

If Balzathar is alive, the party can let him take her to Moonrise Towers
If Shadowheart is in the party, she can kill the Nightsong and become the Dark Justiciar she always dreamed she'd be.
Dame Aylin can be set free, resulting in a battle with Balthazar and requiring Shadowheart to be convinced to spare her.

If Shadowheart is not brought along, then she immediately confronts the party for denying her the destiny she'd always dreamed of. She leaves the party. Additionally, the Nightsong can only be killed by Shadowheart - otherwise, attempting to do so does nothing but annoy Dame Aylin.

If the party lets Balthazar take the Nightsong to Moonrise Towers, then he tells them to meet them there to receive Ketheric Thorm's favour. Once the party arrives and speaks to Disciple Z'rell, she only lets them proceed if Resolve the Abduction is completed. The party must kidnap Isobel from the Last Light Inn to be allowed to see Thorm. If Isobel is already dead, then Z'rell lets that party up to face judgement.

If the Nightsong is freed, she thanks the party. If Shadowheart spared her, then she throws the Spear of Night into the abyss of the Shadowfell. However, Dame Aylin grants her a new weapon as thanks - the Moonlight Glaive. Then, Aylin flies off to face Thorm, starting Defeat Ketheric Thorm. After leaving the Shadowfell, Lady Shar subjects Shadowheart to unimaginable torment before sending her back to the mortal realm, and Shadowheart loses her favor. Once the battle with Thorm is over, Aylin and Isobel, if she is alive, stay at camp.

If Shadowheart kills the Nightsong, she becomes the Dark Justiciar and gains the Shar's Spear of Evening. However, the party loses a valuable ally in the Nightsong.

Where is your quote from? I don't understand where the threat to the inn is coming from unless they assume that if you kill Nightsong you are siding with Thorm. ('Gnarly' is the wrong word there).

I've seen a couple of YTers take out Nightsong by mistake with an AoE during the fight with Balthazar but she is back up before the fight ends.

Last edited by Beechams; 24/09/23 12:32 PM.