I agree that the encounter leaves a lot to be desired. I have only done the encounter on Tactician.
It is very easy to loose this battle in two rounds. If you loose initiative, it hard to recover. Isobel�s AI is bad. She often does things that endanger herself.
I think the game should give you some way to prepare before the battle starts. Maybe a warning that scouts have detected winged horrors probing the the defenses, or something like that.
I also agree that the fight should not end with Isobel being knocked out. The enemies should have to carry out Isobel while you have an opportunity to fight and defeat them, until they are able to get Isobel across the bridge. All or most of the people of Last Light should have Selune�s blessing, after Isobel gets knocked out. So, maybe you get some shadows infiltrating town, but nothing quite as severe as the current transformation.
