Averse Sefira was formed in 1996 by guitarist and vocalist Sanguine Mapsama and bassist Wrath Sathariel Diabolus.

Four years after Battle's Clarion, in 2005, the band returned to the studio to record their third full-length album, Tetragrammatical Astygmata.

A newly found sense of harmonics, similar to Immortal's Pure Holocaust, aided in the creation of the band's sound as well as connecting it to the contemplative moments.

[1] Around Battle's Clarion, they "explored a more death-oriented sound, and helped mold the style of the Texas outfit into something a bit more developed".

One of the things that makes Advent Parallax effective is the fact that you can actually understand the lyrics that are coming out of Mapsama's mouth.

All things considered, this early-2008 release is a respectable, noteworthy example of an American band with a very Scandinavian-influenced sound" wrote Alex Henderson for AllMusic.

He is also inspired by some magical, "particularly ones dealing with Enochian magick", and the Old Testament, "only because it portrays god and the angels as destructive and terrifying.