Alveus Lacuna
Taxiarches


https://witchinghourproductions.bandcamp.com/album/litourgiya
Polish band called Batushka. I think the intention is blasphemy, but that's not totally clear. The chants sound unaltered to me.
Need someone who knows Church Slavonic to listen to the whole thing and tell me if they've altered the words, or just left them in the normal Christian way.