for arson. Tveitan retreated to a property owned by his family to compose much of what would later become Anthems to the Welkin at Dusk, which was recorded after Haugen's parole. In 1995 the cult album Blood Must be Shed, by Zyklon-B was released featuring members of Emperor and Satyricon. Tveitan played synth on the album. In 1998 Tveitan and his wife Heidi Solberg Tveitan—who at the time used the stage name Ihriel—formed the experimental band Peccatum. Tveitan offered his iconic synth sound as well as clean and black vocals to the project. Peccatum would eventually becoming his main project until its termination on 4 March 2006. In 1999 Emperor released IX Equilibrium, Tveitan's third studio album with the group. Two years later, in 2001, Peccatum released their second studio album, Amor Fati. In the same year, Emperor released their fourth and final studio album, Prometheus: The Discipline of Fire & Demise. 'Prometheus' was entirely composed by Tveitan and featured more complex orchestration than previous works; though significantly less synthesizers than before. It was at this time that Emperor mutually decided to dissolve, leaving Tveitan and his bandmates with more time to focus on their various side projects. 2004 saw the release of Peccatum's third and final studio album, Lost in Reverie, with an EP titled The Moribund People following the year after. On 30 September 2005, Emperor made a surprise return at Scream magazine's 15-year anniversary party at Rockefeller Music Hall in Oslo. The show was kept top secret, only known by a handful of people. The band played three songs. This was to announce the reuniting of the band for a few shows around Europe and America in 2006, namely at Wacken and Inferno Festival. Solo albums 2006–2010: The Adversary, angL, and After In April 2006, Tveitan released his first solo album, The Adversary. He recorded and produced the album by himself, with the exception of drums which were contributed by Asgeir Mickelson, and guest vocals on the track "Homecoming" by Kristoffer Rygg of Ulver. The album showcases his progressive influences as well as heavy metal, black metal and classical music. The Adversary was recorded at Symphonique Studios in Norway and was released on his label Mnemosyne Productions, which he founded in 2003 with Starofash. A video was made for the opening track, "Invocation". He released his second studio album, titled angL, the following year, featuring Lars K.