I had technical difficulties and little time to play in the recent days, but I welcome your post, and I tell you where youare:
in the end-area of BG2. It is a pocket-dimension in the Abyss, where you'll be trialed, and fight Irenicus the last time (big-big bossfight coming!). The eyes on the door told this clearly.
Take them as
my watchful eyes. Although I'm not Helm
But for you, unless you have some backup save, there's no turning back. Hope you stuffed all precious cargo in the Watcher's Keep or at your characters!
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I went a little further in my version, and yet did not immediately encountered the Xan/Montaron quest. Good for me. Went to the Graveyard District, and used a prot. from undead scroll to rob primaly the Crypt King, and it even lasted through all minor crypt in the area. Found a Staff of Curing, although is is not usable despite told class-restrictions which does not apply bards. Whatever.
After the tombs went down, killed spiders, and even got the Spider Figurine! Dealing with the spiders on the way was passable as long as it happened one-on-one (defensive spin needed against sword spiders), and summon monster (II) was used at the gate of the dome, mainly as there spiders don't reside, but appear. Strange was for me to see how much stronger an ethercap was compared to an ogre berserker.
Inside I launched a fireball, ran out, waited for regeneration (fortunate nothing followed), ran back and launched a second fireball after I was sure it'll clear the room. As only low-health mutant spiders are in aside the chief this works good. I wasn't even got hurt by anything but my own fireballs, and that wasn't that harmful at all. On top of the figurine the ioun stone (HP + thaco) and the spells are also nice.