This seems a bit underwhelming to me. Is this for commander or something? With shroud and a way for the opposing player to turn off shroud without spending a card (block it, then use a removal spell on it), this seems an awful lot like a vanilla beater or a hexproof defender. The blocking clause doesn't seem to do much if you're using it as a way to get rid of shroud permanents, because the defending player won't bother sending out their shrouded creatures to block this unless they're already in a losing position that they can't deal with this.

Please tell me that reading six lines of text on a mythic rare makes me more excited than the realization that my otherwise french vanilla creature sometimes turns into an effectively vanilla creature during combat.

It's not even as though the flavor is a hit either.

Um, yeah; that's just weird. Slap hexproof on instead and have done with it. (Though; uh, how is that mythic either? It's an efficiently annoying creature, but it's not exciting.)

It's specifically you that may target it, so at least you don't need to worry about your opponent blocking so they can cast removal. But yeah, this isn't at all mythic-worthy. Also, my first thought when seeing the name on the recent card page was that it would be Mirko Vosk.

If it's an "Embodiment of Darkness" why isn't it mono-?

I am looking into better designs for this slot. It's embodiment of darkness, because the BG horror faction is a group of monstrous creatures wreathed in shadow. This is represented by Shroud, which I've brought back as a set mechanic.