That is impossibly beautiful. I'm a calligrapher myself, and I've seen cyrillic calligraphy before, (I can 'read' cyrillic but can't understand any language written in it). But I haven't seen anything like that.
I'm bulgarian, but ican barely read it, because it's old caligraphy, but from what i CAN understand, it says: "Terrible Crowd It is immortal, immortal is the crowd, because it is from chaos born. The crowd ?bought? the evil, of fate it burns, heading towards from beyond. A thirst for blood, so hideous, frightful evil pyres. There is no age, death is insufficient."