A compilation // best-of album is particuarly succesful when an artist has such a broad range of work that a single album makes for an insufficient introduction. This is definitely the case, as Xihilisk works his range of black metal, experimental electronics, noise, post-rock, and ambient soundscapes. Where they most impress me is that even within such a broad spectrum of styles and sounds, there is always a consistent expressive voice. Xihilisk definitely has a cohesive sound, even if traditional genre boundaries are incapable of expressing // confining it.
My favorite track on this probably "Chysalis March", which gradually builds and builds until it soars in a crescendo reminiscnet of fire alarms, a symphony orchestra, whales singing, and norse-god Heimdallr staring into the future.
The cherry on top: he's got a very progressive attitude towards music distribution (i.e., his album Fuck the RIAA). Here's a link to his whole discography he put on his blog.