Originally Posted by Niara
Bear in mind - the intention of Friends is to negatively affect the disposition off the charmed person once they realised you used magic on them. 'Hostile' in D&D is a dispositional state, meaning that they will generally not want anything to do with you, will not be inclined to listen to or believe you, may threaten or warn you away, and will generally be hostile; it doesn't mean "They will attack you".

Translating into a video game, where 'hostile' has a more tangible and hard-line definition, this is often misconstrued to the point were a creature charmed by such a spell will go 'red border' and literally turn combat-hostile at you once it ends, and that should not be the case unless they were already inclined to throw down with you. If this is happening here, I'd encourage people to submit it as a bug report to Larian's formal bug form (Here), and give the feedback that it shouldn't do this.

Agreed, most NPCs who have been turned hostile by Friends and other attitude-changing actions of the player shouldn’t then throw their lives away by attacking a better armed adventuring party that outnumbers them four to one. Far better for them to refuse to interact with the party. Unless, as you say, they are inclined to/designed to be suitable for fighting you anyway. That arguably could apply to the duergar on the landing stage though.

I confess I’ve avoided casting Friends in BG3 just because I’ve been traumatised by poor implementations in the past. I also wish the spell would force a WIS save for the NPC to notice you’re influencing them, but that might make it too useful and anyway I suppose is about DND rather than BG3, not that I’m knowledgeable about the former.

"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"