I just completed it and yeah, he hits like a ton of bricks. My advice is to make sure you have some high level potions on hand, have the second wind and bloodbath from the cross job skills and be ready to move. I used the samurai shield (3rd eye) whenever it was ready and used the Hissatsu: Kaiten to power up the Midare Setsugekka (3rd tier special attack) and used that as often as I could. Make sure to take advantage of the buffs and debuffs from your different combos too. If you can avoid the aoes you should be good. Hope this helps some.