I’m not sure that I’ve quite cracked this one yet, but it has potential (win record: about 50% so far).
What you want to do here is keep the board relatively clear through the first few turns until you can land Atris. Atris will carry you through the next couple of turns until you play Gyruda. Ideally, you want to hit Thasa or Spark Double to keep the trend going. You will win by drawing more cards that your opponent and by undercutting their plays with efficient removal.
While there are certainly mill components to this deck, it is not primarily a mill deck. I’ve beaten opponents the good old fashioned way by attacking with evasive creatures. I’ve won by milling my opponent out. I’ve even won via Jace, Wielder of Mysteries by building a wall and emptying my deck. But most of the time, this deck wins by sneaking through two to four damage a turn that the opponent can’t block.
Atris is a blast to play with because of the mini-game aspect of their enter the battlefield ability. It feels great to take the face down single card that turns out to be exactly the spell you need. It also feels great to take the two cards face up and see the single-land bluff hit the graveyard.