You're not going to damage it much with those spells, but the cumulative effect makes it vulnerable. You have to hit it three times with any of those spells while it is in a single form (e.g. the troll-like creature or the spirit) before it is reduced to less than 40% of its HP in that form, and then it will lose its ability to transform and you can kill it. You should see the G screech and burn when it gets hit with a spell it doesn't like. The Gremlich audio is actual field audio of a gremlich heard in the wild. Which spider with the drow?
The last spider,the mega one that fills the room on its own. My party is level 7-8 and have to use uber fraggie/scathie weapons to kill it,as I can't reach the AC34 with my weapon bonuses,and spells forget it. I see the Gremilich catch fire,but I just can't get the 3 spells to work due to SR before it changes. Oh before reduced to 40%,oh crap,I go gang bang it mixed with spells,no wonder...So cast spells then hit it. :sadblinky Oh bugger,sorry Gaer,I hate you! Cruel man..hahahaha. Oh ps is there a list of spells useable????
Searing Light, Flare, and Faerie Fire, I believe. Light spells. I thought it was kind of funny to think that someone might cast the Flare cantrip on it in desperation and then see it recoil and screech in pain. :biggergri
Oh I got the Rabbit Hole thingy and was told how to kill it for a sharp fee. Pity wish Mona did that,lol. Flare is fine,appropriate regardless of level. But isn't daze a light one? Miss the Sunburst spells,heh.
It appear to have no challenge rating in it's mob, so you'll get no XP at the high level you're at. You'll probably get some XP when you report back to the person who sent you on the quest, and the quest gets completed.