It's really easy once you get the hang. Took me give or take 30 attempts to learn to do him pretty consistently, (altho i killed him on my 5th attempt as a fluke i guess haha)... it was harder for me as i was only 75 mage 70 range at the time. I made like a rotations thing which might help:
Let me know if u have any questions.
(green = rng, blue = mage red = melee, yellow = jad)
also, the dots show you where to stand.