Siren is a main protagonist appearing in the game. She is the female equivalent of the Gongbat, who also shares the same trans mutative abilities and similar design. She is an ancient and powerful spirit creature that holds a more aggressive personality than that of her counterpart. In order to keep balance in the world, she also acts as half of the protective mystics of sound. During the main storyline to Gongbat, she is kidnapped by Hark in order to find a means of dimensional travel.