The trio of Corvus, Necron, and Kryth, better known as Korgonthurus, aren't fucking around. The Finnish trio serves up Black Metal plain and simple, without any outside influence or digressions. Riffs, Satan, Evil, and that's it. And really, what would you expect? Like the aforementioned Sargeist, Korgonthurus has ties to Horna, one of the best known and respected cult Finnish Black Metal bands. I still prefer Korgonthurus and Sargeist to Horna, perhaps only because they stick to the formula with an almost orthodox devotion. Here's Korgonthurus' Root Of Evil demo from 2001.