I'd level up a few more levels. 27 or higher would be fine.
As others said, Ice Shields help. Keep Ice Shields on two of your allies and give them 1-H weapons (e.g. swords, axes/hammers).
You can purchase a Storm Spear and give it to your melee fighter. Mateus is weak against thunder-element, and this spear should deal high damage to him.
When you see on the combat log "...readies Blizzaja", swap an Ice Shield to reduce the damage from that attack. Then re-equip the Storm Spear.
Take the Ice Azers out first before you go for Mateus. Use the Thundara spell to target multiple ones at the same time, but make sure that Mateus isn't one of the targets as he has Reflect on. You don't want your spell reflected back to you.
You can give this ally a Storm Staff during this time to inflict more damage with Thundara.
Put Nishijin Belts on everybody to protect from Sleep. Mateus casts this a lot during the battle.
Use Esuna gambits to get rid of the Sap status ailment that comes with Blizzaja.
Set your healing gambits on your other two allies to keep everyone's HP at 50% or higher. You can purchase the Curaga spell at this point. Have one ally use Cura and another one use Curaga.
Have a stock of Hi-Potions to use if your mana gets too depleted.
Before you enter the battle, buff everyone up with Protect and Shell.
Although Quickenings can do well in getting rid of the Ice Azers if you pull off a good enough chain, I wouldn't recommend trying them because if it fails, you will be left fighting with depleted mana.
Reply With Quote