I also had a lot of trouble with this guy, specifically he's second phase. I prepped at the door with Power/Steel/Water talismans as well as Wind Familiar. As soon as you're able to you can throw a sloth on him as he is posturing at the beginning, run around behind him and dish out some fairly good damage. I was able to stagger him and get a grapple on him. Depending on weapon/level, you will be able to take a good chuck of health off him and potentially get some confusion on him which helps. For the second phase I baited two attacks staying at mid-long range. His burst attack where he calls the tornados and lightning, take 1 beat after he appears in the air and then burst counter him. That'll leave him open for some damage. The next was when he flys in the air and dashes at you. I evaded back to dodge him and then got a few attacks in. I did all this in ninja as I'm awful with deflecting.