Well, the first 10 or so times went with trying to memorize his patterns and attack styles... xDDD But then, when I got the hang of it, my basic strategy was Dodge - Attack - Heal. Pretty much the normal one. :DDD
The Sin Heartless Angel or whatever -attack was easy to prevent, but I never found out how to get out of that massive meteor attack uninjured. D: Gladly it didn't deal that much damage. x3