Do you mean Mateus? That was a hard battle for me as well. The ice shields will help, but try to get quickenings on a few more characters. Then open up the battle with a quickening, and hopefully the ice azers will be killed. Mateus likes to use slow a lot, so use haste on any slowed character. His Blizzaja attack also can cause Sap status, so cast Regen on anybody inflicted to negate that.

If you get more quickenings for your characters you get more MP.