Hi,
It's not casting entangle that's a problem, it was casting an entangle at Bassilus and his minions before they turned hostile. It's worked well before with other combats. I don't think he turned invisible or anything as usually the spell is wasted and you get the message "target lost" or some such - but they just kept waving their hands over and over, like there was a casting time of 10 rounds. I started casting it just before the conversation started with my 2nd main character, an Illusionist-Thief, who pretended to be mother. Then he turned hostile and the druids just kept wiggling and none of the minions went hostile until they were attacked themselves.
IDKITIAB = I Don't Know If This Is A Bug
By the way, I read your reply about Greywolf and I take back everything I said about combat being easier - I found Greywolf and Bassilus easier (although I have enough experience to meta-game those and pre-prepare), but the Ogre-Mage with the Nereid and all those Sirens were HEAVY. I had to retreat, level up and go back to get that ogre. All for 975 XP, whereas just murdering the Nereid in the first place would have got me 5000 XP. I never did really understand that encounter. I thought we got a rep boost for saving her, but apparently not.
And a DRACOLISK!? I need a new spell - Power Word: Reload!
Cheers
~