Mats Levén (ex-Candlemass, etc.) has officially joined Prins Svart as their new singer. With this news, the band have also released a new song titled “Speglar Och Dimma.” That track is from the group’s new album “Sanning Och Makt,” which will be released on April 23. Prins Svart commented: “Mats is Sweden’s best singer and…