Beat him first try. Kaim, Seth, and Ming all Level 99, Sarah was 97 and Sed was 87.
I did use your strategy, and it worked out well
I didn't lose a single person. Plus I did it all at 2:30am this morning, checked leaderboards and was first to do so with ntsc console :P
The mini-bosses did NOT drop the new spells for me, which were reported to be random drops off them. Ugh... looks like ill be doing some grinding down there on the mini-bosses.