The Threshold Between Life and Death! The Battle of the Underworld!.Because of Schiller's Praesepe Underworld Waves, Yuna leaves the earthly plane and finds herself in the deathly Hill to the Land of Spirits. Terrified by the sight of the souls of the deceased and visions of her sordid past, Yuna cowers until the arrival of Köga, who suffered her same fate, and losing his temper due to Schiller's mockery of Aria's death, Köga is consumed by the Darkness Cosmo inside him. Managing to calm down Köga, Yuna engages the Cancer Gold Saint in battle once again, and drawing from her bonds to Aria and her comrades, she finally finds the strength to miraculously awaken the Seventh Sense, overpowers his Sekishiki Meikai Rinbu with her Aquila Shining Blast, and toss Schiller into a lake of boiling blood, killing him.