product description the battle system is real-time based, similar to those of the star ocean games. only one reyvateil can be present in battle. the player controls one of the three vanguard (support/attacking) members, and the ai controls the other two, though the player can change the character he/she is controlling at any time in battle. the purge system is a key element, as it allows reyvateils to use their high-level song magic. however, 'purging' also has importance for the vanguard characters, as it allows them to use their best attacks.synopsis ar ciel, a planet that was once lush with many prosperous inhabitants.the humans of this planet created a new species with the power to convert songs into various energies, reyvateils, and boasted about their highly advanced civilation.however, a foolish release of immense energy triggered a global catastrophe that changed the world. the planet was shrouded by deadly clouds, called the sea of death. with the loss of the land, only three artificial towers were left for the people to reside on.the world of the third tower, sol clister, is practically controlled by reyvateils. the state of reyvateils who reside in the upper part of the tower, clustania, exert their authority over most other nations from the top of the world.clustania aims to establish a society that consists only of reyvateils and "purified" human slaves. to acheive that goal, they carry out genocidal campaigns, called cleansing, upon the human communities that dare to defy them. they literally annihilate cities and towns, turning them to ruins.key features: form a party to explore the world, visit towns, and enter dungeons earn dive points in combat to enter a character's subconscious mind