Michael on Sandalphon is identical to Ra on thoth&Sopdet. He's easy but orb screw sucks.

Listen to Obryn on this one. Realization that Raphael is the real boss and Sandy just makes sure you don't get sloppy, helps. That's how several of my dungeons have gone; the boss isn't hard, I can just heal up. It's getting there that's hard, and saving skills for the boss you'll never get to is less efficient than getting to the boss and still having a chance at all.