That said, if I recall correctly, that particular encounter at Moonrise does have a unique interaction whereby the Harpers decide to engage on their own if you wait long enough. So there is a possibility that this behaviour caused this issue, whereby their auto-engage activated when you selected another party member that wasn't in combat.
I am certain I did not click the “End Turn” button for Gale, but rather directly clicked my Tav’s portrait instead. And suddenly I heard Jaheira shouting stuff while I was steering my Tav and the other attached companions closer to the stairs at the entrance.
For comparison, I used sneak again immediately after the battle, when I went up the stairs of Moonrise Towers to the first floor and approached the Necromites waiting there. Once again, Gale was at the front, cast Glyph of Warding, then I switched back to my other characters to have them follow. And this time, as expected, Gale patiently waited, keeping combat frozen in time, without the enemies simply continuing the turn order. But of course, there were no Harpers involved in that fight anymore.
So is that auto-engage behaviour of the Harpers the same thing that activates when you decide to climb the towers on the outside? I’ve heard that doing so always results in Jaheira dying, as you’re leaving the Harpers to fend for themselves on the ground floor.
Seems like this just adds to the list of uniquely annoying Harper behaviour. On my very first playthrough (Balanced), I used Cloudkill in the entrance area, and the Harpers blamed me for the death of one of them who was stupid enough to walk into the Cloudkill. (They got the “Witness” icon, and I remember being afraid that everyone would attack me once I returned to Last Light Inn, or that the “Enemy of Justice” tag would carry over into Act III, with all the guards in Baldur’s Gate constantly chasing me. I was mentally prepared to reload back then, to do the entire Mind-Flayer Colony and the Myrkul fight again. Luckily, it ended up not being necessary.)
On a later Tactician / Custom-Mode playthrough, I used Hunger of Hadar instead of Cloudkill, and a little further down on the floor, rather than on the staircase itself.
Somehow that ended up working better, even though the enemies themselves of course use Hunger of Hadar, too. Perhaps placing the AoE spell a little further away from the approaching Harpers prevents them from simply rushing into it, and encourages them to go around it from the sides instead.
In turn, does this auto-engage behaviour of the Harpers also exist if you spear the Nightsong? Because as far as I recall, only Jaheira waits for you at Moonrise, then? (Of course, that auto-engage behaviour could still apply to her alone, but it would seem rather unrealistic to me that she would attempt to storm Moonrise all by herself if you e.g. decide to climb the outside of the tower in such a scenario.)
During the rooftop fight on my current Honour-Mode run, Nightsong ended up being as useless as many had warned me she would be on higher difficulties. So I was mentally preparing to say, “If I fail the Myrkul fight and have to do another run, Nightsong is getting speared again.”
Luckily, she redeemed herself by doing a lot more work in the actual Myrkul fight. Though I dare to believe I could have managed without her — most of the damage was done by plenty of Scorching Rays, from my Fire Sorcerer Tav and Light Cleric Minthara.
The plan from here on is:
Sanctuary the Emperor during the Astral-Prism fight, ally with Gortash, skip House of Hope / Iron Throne / Steel Watch and the Annals of Karsus, maybe do Cazador and House of Grief, invisibly pass through Manslaughter Chasm and yeet Orin into the abyss with some invisible character using a Cloud-Giant Elixir. Then invisibly skip the courtyard fight and have Gale blow up the Netherbrain.
I’m getting cautiously optimistic at this point, as my characters barely lose any health anymore, between unkillable Abjuration Gale and multiple characters getting upcast Aid, Warding Bond, and Death Ward from my camp hirelings every day, while multiple wear adamantine gear that prevents critical hits.
Those fights that did make me slightly nervous in the moment, despite my planning and preparation were:
1) against Kar’niss (had forgotten to bind Wyll’s hex weapon, silly oversight on my part, and then picked dialogue options that made the Harpers run away with the moon lantern — while I thought I’d still get to pick the “attack” dialogue option later, rather than the dialogue ending prematurely — which I was able to rectify at the last moment by going into turn-based mode and attacking them before they could despawn, which would have forced me to do the Isobel-Marcus fight to get the pixie blessing);
and
2) against the Meenlocks (went into the fight with Calm Emotions to prevent getting frightened, and with twinned Haste — but due to a slight timing error on my part of when to apply Sanctuary to which concentrating character, one Meenlock got a hit in on Shadowheart, who then lost concentration on Calm Emotions).
