Recommended by Monasterium Imperi:
Related dark choir / gregorian ambient
Dark Synths of Terra
Prometheus Sanctuary
Dungeon synth & lo-fi rendition of Monasterium Imperi's debut album. Grimdark synth for the Emperor's glory!
Evangelikon
Cryo Chamber
Also a project by Scorpio V, Metatron Omega delivers lush dark ambient with powerful and dark church choirs
Also recommended by Scorpio V.
Chants From the Inner Monastery
Scorpio V
Dark gregorian & byzantine chants with authentic vocals by Scorpio V, coupled with ritual ambient.
Also recommended by Eshaton and Forest of Yore.