He's really hard to hit all right, but I managed very early in the game using a bat of striking that had frost on it and a couple of minor potions of healing (for when the frost wore off and I didn't manage to hit him for a while).
That was before I ever found out about scorpions - and now I refuse to use them because, as others have stated, they distort play balance too much plus they are just so damn heavy to lug around.
-Peter
