A brilliant tip ( I feel ) is if you use Triple on your party members ( use Cerberus when you get him ) then use one of your party members to cast Aura on all the members, then immediately after this has happened, use a Holy War ( or 3 Heros ) this means that you will be able to use your limit breaks and not receive damage - also, being in Invincible state means that your Aura lasts much longer.
This is very useful when fighting Omega Weapon ( the hardest boss in the game - with 1,161,000HP!!! )