Basically, just dodge into his attack until you're behind him. Hit him a couple of times, rinse and repeat. However, be careful, when he shoots arcane barrage (yes, that's a WoW reference), you may not be safe behind the big pillar in the middle of the room. I sat there just waiting for him to finish and it went right through and almost KO'd me. I was like WTF? After that, I just kept on him being aggressive, dodging his attacks and swiping away. Bolt paper is also effective.