In his first phase, my strategy is always to get under his right side (my left) after his attacks.
On his second phase, I strafe/dodge to the left most of the time.
Do not be greedy on both phases especially on the second one. Also, his second phase seems more aggressive so you got to be careful on healing.
I finally killed him after hours of trying to get through to his first phase that is why I never had the time to familiarize myself with his attacks on second phase. -- Watch live at / hope_talledo