Manntra's musical style is characterized by a fusion of traditional Balkan folk music with heavy metal, incorporating elements of electronic music as well. The band often employs traditional instruments such as sopele, the tamburica and diple, alongside electric guitars, drums, and keyboards. Their music is notable for its dynamic rhythms, driving guitar riffs, and powerful vocals, often delivered in both Croatian and English. The band's lyrics frequently deal with themes of spirituality, mythology, and personal struggle, which are often drawn from Croatian folklore and history. Overall, Manntra's sound is a unique blend of different styles, creating a distinct and compelling musical identity.
