Your damage is a little low but you can definitely kill it with good execution.
Start on the stairs up where the boss is instead of pulling him to a side. Use lust at the beginning if you haven't been. You can move to the end of the hall after the first Unseen Strike and then continue as normal. Make sure tornadoes are being placed behind the marker/future markers in a semi-circle. Pretty basic stuff, you've only done like 15-20 pulls, you'll get it soon.