Epsilon (stylized as õpsilon) is Blood Stain Child's fifth studio album and first release on Coroner Records/Pony Canyon. It's also the first and only album to feature vocalist Sophia and drummer Gami (after the departure of vocalist Sadew and drummer/founding-member Violator). All compositionsâÂÂexcept "Electricity," which is composed by AkiâÂÂare by Ryu, while lyrics are co-written by Sophia. This album was pre-sold during A-Kon from June 10 to 12, 2011. And, in this event, nine of the new songs (including the European bonus track, "Royal Sky") were performed. As of June 7, 2011, Pony Canyon released forty-four second samples of each song in the album; a full sample of "Sirius VI" debuted, through Internet radio, on May 26, 2011.