Gurthang
The Polish Black Metal scene might be (one of) the ‘richest’ from Eastern Europe, I think, so there might be an impressive amount of qualitatively high-standard bands dwelling around there too. And one of the top acts – at least, this is my personal opinion, for what it’s worth – is this one: Gurthang. In essence, it is the brainchild of one A.Z.V. aka Azathoth, whom you might know as well from, for example, Cosmic Despair, Beyond Life or Azathoth (defunct in the meantime).