Revision 1

Siren becomes available as an esper after the Chapter 1 battle at Siren Tower. She costs 50 MP to summon and remains for three turns. Her commands include Bio, Water, and Watera; her final action, Lunatic Voice, damages the enemy group and can inflict Sleep or Silence.

Siren Tower battle

The opposing Siren is weak to lightning and can inflict Charm. Monk's Prayer Beads protect their wearer from Charm; prioritize keeping the healer and Rain able to act. Cloud or Warrior of Light can supply lightning attacks. Let Fina keep the party alive while Rain draws attacks, then use the stagger opening for damage. Winning also awards a Magicite Shard.