Playing on hard I had a pretty good flow going on Kirk. Started out with about 10 life bottles. This was a mistake because after about 14 minutes of grinding him I managed to whittle him down to 2000hp before I ran out of bottles and he proceeded to annihilate my party rather quickly. In pure spite I switched the difficulty all the way down to easy and proceeded to mop the floor with him.
I don;t think another boss has ever made me feel so vindictive. ;p
Ok, I admit it. I used an divide all on that fight and still lost. It was basically a war of attrition and Kurt still won. Whatev, I was at level 40. I don't think girding would have made a big difference.
I ended up using a fair few healing items and life bottles. Party was probably around the level 60 mark (from memory). Though keep in mind that the only was I've played the game being able to, it full auto battles on the highest difficulty possible. Unlocked Chaos at Orlen (that's wrong, isn't it?) Woods on the first play through and haven't looked back. The battles get a lot easier when your starting gear is at +99.