Mysterium tremendum et fascinans



A Terrifying And Fascinating Mystery is a song sung by LUMi with Ruby Allegri, Luka Megurine, Maika Hayashi, and Yukari Yuzuki doing the chorus. It is the two-hundred-and-sixty-sixth track, the two-hundred-and-sixty-seventh track, and the two-hundred-and-sixty-eighth track in Other Vocaloid Songs 50.