When entering Raul Hills 1 ruins special stage with the devils, make sure you have saved the game. Also, equip some Revival Gems to all of your characters so that if one of the devils does the "BA-BOOM" move, your party will take about 4,500 damage. The items you can find here are Sonic Belt (+40 ACT), Fairy Egg (no attack spells), Blackquartz Helm, Soul of A Hero (carrying it doubles experience earned), and another item that doubles SP earned.