!T.O.O.H.! is a Czech progressive death metal and grindcore duo formed in 1990 in Libice nad Cidlinou under the name Devastator, later changing their name in 1993. The two-piece outfit — consisting of Schizoid on drums and vocals and Humanoid on bass, guitars, and programming — blends death metal, grindcore, and folk-tinged progressive elements into a singular, difficult-to-classify sound. Their discography spans six albums, from the 1999 debut From Higher Will through the politically-charged Svoboda slova in 2020, with lyrics evolving from early gore themes toward social and political commentary. They remain one of the more idiosyncratic acts to emerge from the Czech extreme metal underground.

Alkaloid is a German progressive and technical death metal band formed in Munich in 2013 by former members of Obscura, Triptykon, and Dark Fortress, including vocalist Morean and drummer Hannes Grossmann. The band's three albums — The Malkuth Grimoire (2015), Liquid Anatomy (2018), and Numen (2022) on Season of Mist — fuse brutal technical death metal with science fiction concepts, polyrhythmic complexity, and unexpected melodic turns, earning wide critical acclaim within the progressive death metal community. Their dense, intellectually ambitious compositions set them apart as one of the more distinctive acts in contemporary extreme metal.

Barren Earth are a progressive death metal band from Helsinki, Finland, formed in 2007 by musicians drawn from several established Finnish acts, blending melodic death metal, progressive rock, and folk influences. Their Peaceville Records debut Curse of the Red River arrived in 2010, followed by The Devil's Resolve (2012), On Lonely Towers (2015) on Century Media, and A Complex of Cages (2018). The project serves as a creative outlet distinct from its members' primary bands, consistently exploring atmospheric and compositionally complex territory.