S1·E14 Mysterious Assassin

Schneider gets Haru, Elie, Plue, and Griff lost in the caves and tunnels of Tremolo Mountain. While they decide to rest for a while, Schneider attempts to murder Haru. Much to his chagrin, he is stopped by Musica in the disguise of a Shadow Guard. Musica explains that he came to Tremolo Mountain to take the Rave Stone for himself. Haru then has a match against Musica, but Elie intervenes. Musica decides to help the others in finding the Rave Stone. Plue helps them find a secret passageway. An inception on a wall, written in an ancient language tells that the Rave Stone is inside. Once inside, they are confront by a Knight of the Blue Sky.