Yes, half-assed comes to mind. But it *is* just an expansion after all...
You can't target an improved invisible creature, so you can't remove their immunity, I believe that's the problem? True Sight?
Anyway, ToB was originally meant to be BG3, but they seem to have just gave up and did a half-assed Xpack instead. That's why I installed Ascension - hoping it'd add a bit of life. But as it stands I'm struggling to find purpose to continue BG2 normal - it's all just too easy... but more than that, it really is boring. Maybe I've just played chapter 2 way too much. Yea, I'll go to spellhold and sort things out.
Wild Mage
Wiiiiiillllld.... Mage
See how easy a time of it you have when, right in the midst of a battle, your Mage casts fireball x2 on your party.