Use blind. For the love of all that's holy, use Blind. Put one point into Witchcraft - just one! - and then revel in the glory that is Blind.
And, of course, you were given great suggestions in the posts above mine, too. But, seriously. Use Blind.
Haha, with Drain Willpower it's the second-most-broken combat ability in the game (after Leech). Every boss in the game (including the last one) goes down to this combo, they just stand there and do nothing and I've never had it miss.