In 1987 he founded Allerseelen as his own group, named for the Catholic festival of All Souls' Day and also for the song by Richard Strauss and a chapter in Blue of Noon by George Bataille.

[1] After a series of cassettes, in 1993 Petak released his first CD, Cruor, a purely instrumental compilation of work since 1989 with a Mithraic and shamanistic focus and cover art of an underground temple.

Some of the tracks were reissues, including "Alle Lust will Ewigkeit", from a 7" record published in homage to Leni Riefenstahl's film The Blue Light, and "Feuertaufe", from a French Mithraic compilation.

Others were inspired by or pay homage to Jünger, Nietzsche, Julius Evola, and Igor Stravinsky; the printed material quotes the French philosopher Jean Baudrillard and includes images from the occult film Lucifer Rising.

[1] With Neuschwabenland (2000, named for an expedition to the Antarctic carried out by the Nazi regime in 1938–39)[4][7] Petak announced a shift from dissonance to "fin de siècle military pop", which has been credited as the first use of the term.

[1] In 2002 Allerseelen issued Abenteuerliches Herz, again drawing on Jünger, including for its title, but described by Petak as harking back to the French poètes maudits he enjoyed in his youth.

[1] Also in 2003 Petak released Wir rufen deine Wölfe, a collaboration with Moynihan's band Blood Axis, Ô Paradis, and Waldteufel based on work by the German mystic and anti-Nazi Friedrich Hielscher.

A reviewer noted that Petak was now calling his music krautpop or "industrial Folklore", and criticised his over-repetition of samples from "obscure recordings" to build atmosphere and for rhythmic purposes.

[14] Allerseelen's following album, Terra Incognita, so named according to Petak because he did not know at the outset how it would turn out, was released in 2015 and includes reworkings of old tracks as well as new material, with lyrics by Nietzsche, Goethe, and Richard Wagner and several guest artists: John Haughm of Agalloch, Jörg B. of Der Blutharsch, Daniel P. of Arnica, Alexander Wieser of Hrefnesholt, and Robert N. Taylor of Changes.

In addition to Nietzsche, Wiligut, and Ninon Hesse, it includes lyrics by Elisabeth of Austria, Aleister Crowley, Walter Flex, Yrjö von Grönhagen, Yves Kéler, Gotthold Ephraim Lessing, Anaïs Nin, Ferdinand Raimund, Knud Rasmussen, Isabelle Sandy, and Petak's girlfriend, Aida de Acosta.

A reviewer noted that the coalescence of Allerseelen into a group continued, with Marcel P. and Estella Plunket of Miel Noir appearing once more, together with other guest artists including Thomas Bøjden of Die Weisse Rose, Aki Cederberg of Halo Manash, and the Algerian singer Faye R.[17] Petak has also published writings in periodical form as Ahnstern, previously Aorta.