How Do You Defeat the Shadow Fighters on Aeos in Star Ocean: The Last Hope?

Use the in-game Tactics system to set your team's battle tactics to "Gang up with full force" before going into the battle. You want your party members to overwhelm the Phantom Soldiers before they have a chance to really launch their attack.

Take control of either Edge or one of your healers, such as Sarah or Myuriah. This mainly depends on your style of gameplay. If you prefer to jump into the fray and lead the attack, control Edge. If you prefer to support your team while they fight, control one of the healers.

Equip yourself with weapons, armor and accessories that protect against Silence. The Phantom Soldiers have a tendency to cast Silence, which greatly diminishes your ability to heal the party and use other abilities. With these items equipped, you can concentrate on fighting the soldiers without worrying about losing control of any abilities.

Use any items or foods that boost your stats just before you go into battle. Anything that boosts ATK, DEF and INT will be particularly helpful against the Phantom Soldiers due to their high attack power and defense.

Heal your party members often if you are controlling one of the healers. Pay particular attention to anybody that dies during the battle and revive them immediately. Keep lending your support until all of the ambushes are over. While waiting to heal your party, throw EM bombs into groups of Phantom Soldiers to deal major damage.

Use Taunt if you are controlling Edge for this battle. This will make the Phantom Soldiers chase him while the rest of your party attacks from behind. When you create some distance between yourself and the soldiers, use Rising Blade to attack them all at once. Stampede Slash is also effective against the Phantom Soldiers. Keep attacking until all of the ambushes are finished.