I dont want to multiclass.
Absurdely strong end bosses unfortunately are a kind of tradition in D&D computer games.
In BG1 you face a level 17 fighter with amazing stats (Str 18/00, Dex 18, Con 18) and amazing gear (Vampiric Sword +5) and a lot of also really powerful allies with a level 7-9 group. Fix in the original game: use wands and fill the room with summons. Unfortunately they later "fixed" that. You could travel with this character in ToB (though at that point he's not that impressive anymore, also he's still an a**).
In BG2 you face some OP spellcaster that you simply. Cannot. Touch. Not with spells, not with weapons. The tricks here is to keep summon mobs and send them to him until he runs low on spells. Only then you finally can actually damage him, after which he obviously is easy.
In BG2 ToB you face some completely OP spellcaster who even with a full maxlevel group is extremely hard to beat, and theres no real strategy that I know of except keeping to retry, plus of course in the late game the original game is kind of really buggy and just loves to crash in this fight.
In The Temple of Elemental Evil you face a really highlevel demon (dont remember the exact level) at the end that I could only kill with bug abuse. According to original D&D3 documentation a level 10 group shouldnt be able to beat this opponent, full stop. Then I instantly teleported to the questgiver, only to be told that I was somehow too slow to travel there. Another one of the many bugs of that game.
Dont remember much of NWN1 or NWN2, neither of which I enjoyed much, and in NWN1 you would even be solo. I do remember that in the NWN2 addon Storms of Zephyr (by far my favorite NWN content) my group was maxlevel and equipped as well as I could manage and still the final boss needed multiple retries.
