Did the whole of Durlags tower keeping SCS on insane with my little duo party (not gonna narrate it I don't think - too tedious) The only fight I skipped is the improved chess (since you can just potions of absorption + invisibility through it... I mean its seem like its almost intended to be stealthed). The Demon Knight was surprisingly easy - got it on the 2nd attempt. Had more trouble with the improved "Love", "Pride", "Avarice", and "Fear" battle on level 1 since they have some pretty strong regen (and I wasn't maxed out with XP at this point too I guess) In the end wand of monster summoning ogres proved to be MVPs. Did the cultist ambush fight too on return to Ulgoth's Beard but it was so unsatisfying: endless wands of fire scorcher-ray and running round them in circles to proc the invisible assassins - and the fighter-mages with wands of frost are just... well, here's the readme:
The cult consists of:
Cult Guards: 8th level fighters. Their hit points are increased from 39 to 65; otherwise they're left alone. But note that 8th level fighters usually get pretty good battle potions from Smarter Potions.
Cult Archers: originally 8th level thief archers, they're changed into 8th level fighters (more hit points and better battle potions).
Cult Assassins: 8th level fighter/thieves. They get extra hit points and a stack of Invisibility potions (they'll only use them if you have Improved General AI installed).
Cult Wizards: originally 3rd level wizards (in practice), they become 8th level and get Wands of Paralysis (a surprisingly nasty weapon in BG1).
Cult Enforcers: in the original game they're actually listed as high-level fighter-mages, but they don't use any of their fighter-mage powers. I take their classification more seriously: they are now 10th/10th level fighter-mages, though with only L5 spells and below, and they use their Wands of Frost. These guys are very dangerous.
In the end after killing them I just reloaded from before the fight, not like I have a shortage of wands of fire but at xp cap its only really to say "did it." If I am going to attempt Aec'Letec i'll do it later.