Synalon
[12] Conqueror
I usually just do SET after the BT (I assume that's the notation - I mean the move where he sprouts spikes from his back). He'll teleport away before the first hit, you'll be too far away for the chair to hit you, and then the orb will fly in the opposite direction to you and hit him straight in the back. There's probably a better way of dealing with it, but that's what I do for now. I'm not sure about ORB options, though.