Arioch also played guitar and sung in Triumphator in the 1990s and contributed the lyrics to the French band Antaeus' song Sanctus, released on De Principii Evangelikum in 2002.

Mortuus introduced a decidedly distinct and different vocal style to Marduk to that of his predecessor, and it was due to his credentials as vocalist in Funeral Mist that Håkansson contacted Rostén by telephone.

In contrast to Legion, Håkansson has stated that Rostén has shared his interest in enthusiasm for Marduk's lyrical content, which has notably consisted of subject matter such as Biblical tales, Third Reich history and World War II.

In 2012 Rostén also started a new solo project called DomJord, which focuses on electronic music but didn't release its debut album Sporer until March 13, 2020 through Vidfare Productions in collaboration with Norma Evangelium Diaboli and The Ajna Offensive.

[8] In April 2018, Mortuus and former Marduk drummer Fredrik Widigs were accused of purchasing items from the Nordic Resistance Movement (NMR), a Swedish neo-Nazi organization, after sale records for various purchases were uncovered, including Mortuus and Widigs' real names, personal email addresses, and shipment records confirmed the material was shipped to their home addresses.