As stated many times here, combat is terrible. I set the difficulty to normal, because, you know, I expect a reasonable difficulty level. The VERY FIRST FIGHT is pretty much unwinnable, unless you get extremely lucky.
I'm genuinly interested: have you tested this, before you released it? Surely you must have realized that it takes an ungodly amount of tries to beat this, so it should have been changed before release. Well, I'll load a save way before, skip to the combat and set difficulty to easy before. Maybe that'll do the trick...
edit: yepp, that did it. Full mana bar from the get go and beat it on the first try. This should NOT be necessary.