Although death metal and prog metal are usually thought of as two different subgenres of heavy metal, in certain cases, there's really not much differentiating the two.
Case in point, Origin, and their 2008 release, Antithesis.
Although they are extreme sounding in just about every way imaginable (guttural growls, stop-start riffing, metronome-perfect drumming, etc.), the instrumental prowess of Origin's players is mighty impressive here.
But be forewarned -- there's not an ounce of melody detected anywhere (just front to back metallic brutality), as evidenced by such over the top assaults as the album opener, "The Aftermath," as well as "Consuming Misery" and "Wrath of Vishnu," among others.
Whether you love it or hate it, most would have to agree that Origin's Antithesis is certainly death metal at its most complex and challenging.