At the last chapter of Sephy's story mode, defeat the last boss with flying colors and you a dark screen will show up. It will tell you earned the red sword of justice. Start a new story and when you go to the equip screen, the sword of justice will be available.
To get Mar to join your party at the start of the game, talk to everyone on deck, but do not let them join your team. Walk back to the cabin just before you enter Magnus and Cleo run up, say a few lines, and then the dragon will attack. After the fight Cleo will wake you up. You will hear a flute playing. Player mode will switch to Cleo and you will go up the cliff, past the waterfall, and on to Mar.
First play the flute players quest than sephys.. After play zeus to make the spider level alote more easier....!!
If you are losing a battle, pause the game and change weapons (select "Equip"). Now resume the game and you will find yourself at the begining of the fight, with full health.