This is simple. When you defeat the first two dungeon bosses you get a santa Maria from each of them. To defeat Eugene put a santa maria on your two best characters. Put Gre on your team. Put Gre in back and Put Mag and (Chain or Pepper) in front or middle. Use Gre's cheer up heal every one when they are hurt (note: cheer up only works on one ally) Use the weakest hammer attack with Mag. It will still do good damage and it saves TP. Continue to attack and heal and if you die then a santa maria will bring you back.