Andrew Cuneo has done it again. He's taken a rather fun format and designed a deck that could take hours just to win a single game. Those of you who are fans of squeezing every ounce of enjoyment out of your wins (and making your opponents miserable in the process) will absolutely love this deck.
Kill their stuff, draw some cards, and eventually stick a Mesmeric Orb or two. From there, you'll be milling both players' libraries, which will eventually win you game. In the meantime, use the Orb to fuel your powerful delve card drawers. If you find an Elixir of Immortality, you should be able to go infinite eventually, should you deck before your opponent.
Path to Exile and Oust are particularly effective here, as the creature you Oust will likely get milled and Path to Exile causes another Mesmeric Orb trigger (and takes a card out of their library), furthering your win condition.
Should things go awry (or your opponent refuses to do anything), there's still a couple of Celestial Colonnades left to win with. I'm not sure how good this deck actually is, but regardless, it looks really sweet!