Distinctive among the Swedish death metal bands, early Therion combined the Celtic Frost aesthetic and style with heavy old school death metal on several albums, reaching from their roots on Of Darkness... to the epic and melancholy Beyond Sanctorum to the apocalyptic Symphony Masses: Ho Drakon Ho Megas. After that, the band faltered with Lepaca Kliffoth but then reinvented itself as a type of neoclassically-influenced, occult-driven, esoteric power/progressive metal hybrid.