Endvra - Treads the line between several probably imaginary genres, but I would probably describe it as somewhere between flowery Dead Can Dance melodies as seen through a Lovecraftian vision and harsh, spooky, ritualistic noises. Some of their works can feel a bit incongruous, but overall I've found it to be strong and moving music. Their albums that I can vouch for the quality of include Elder Signs (a compilation of quite a bit of their early stuff), Great God Pan (probably their best and most consistent work, very ritualistic, organic, and barbaric. Reminds me of To Mega Therion in a way), and Black Eden.
Tenhornedbeast - Not straying very far here, this project is the solo work of Christoper Walton, one of the 2 members of Endvra, who are no more. He plays in a drone doom style, working mostly in processed guitars, more spooky noises, and thundering bass. What separates Tenhornedbeast from the mass of amateur dark ambient projects out there is a masterful sense of dynamics.The Sacred Truth and its "companion album" My Horns Are A Flame to Draw Down The Truth are strong releases, but they're blown out of the water by the massive, brooding, and barbaric Hunts & Wars.