It has elements of 1. dark ambient and 2. rhythmic ambient/IDM
It is dark, dense, brooding, mysterious, but also rhythmic, with organic, complex, pulsating rhythms. Something like... a bubbling mass of magma flowing through an underworld where ghostly spirits and strange creatures lurk. It must have a sort of soothing effect... not too much sharpness..slightly low-fi...very 'organic' and pleasant in the lower and mid frequencies.
Some of Vir Unis comes close in the rhythm part...but it lacks a truly dark, underground, gothic atmosphere of artists like Lustmord, Raison d'Etre. Hmmm yes.