I think the difficulty for the end, and probably other locations, was being too low a level (30 is pretty low for the end of the game; 33-34 is about average, and it is not terribly difficult to get to 35-37). Doing more quests and exploring more (or just doing areas in a different order) would likely make things much easier, especially now that you have a better idea of how to make an effective character build.
Another..Hall of Echoes question (a bit of leveling discussion half way down)
Finished Divinity II ? Tell us with which stats.Welcome to the forum.
