EDIT: So... like a total idiot, I forgot to put in Selfish Shellfish in the initial decklist. ... It's there now, though, along with a couple adjustments I've made for the day 1 meta. Like I expected, the list is super bad... but I'm having tons of fun playing it!

Fair warning as I write this the day before Sunken City launches--this will probably be a very, very bad deck. If, however, you're like me and don't care about your rank (and enjoy playing "villain Priest" decks), this may be the deck for you!

In theory, the deck has two win conditions: 1) milling out a slower opponent using Selfish Shellfish deathrattles, and 2) controlling the early game against faster opponents, then swinging the board in the midgame with large silenced minions.

The game plan is pretty straightforward, especially if you can read the matchup before the mulligan. Against aggro, mulligan for Switcheroo and as many board clears as you can get (though the dream clear is to go turn 3 Switcheroo into turn 4 Selfish Shellfish + coin + Whispers of the Deep). Against slow strategies, mulligan for Switcheroo, Selfish Shellfish, and Azsharan Ritual. Against Murlock and Mechadin in particular, mulligan for Shard of the Naaru and Shadow Word: Ruin.

One final word about the mill win condition: I'm not completely sure how well it actually works, since the game has interpreted [Hearthstone Card (Xyrella,the Devout) Not Found]'s battlecry in different ways at different points in time. A couple months ago, Xyrella would not trigger deathrattles of silenced friendly minions. However, at some point (not exactly sure when), she was changed to correctly reflect her wording: "Trigger the deathrattle of every friendly minion that died this game"--i.e. she currently triggers the deathrattles of all friendly minions that have died, rather than triggering all friendly deathrattles that have triggered (as she had previously). This means, for example, that if you've been able to summon six additional silenced copies of Selfish Shellfish through Azsharan Ritual and Sunken Ritual, Xyrella should force your opponent to draw a total of 14 cards, enabling your game plan of either burning the opponent's deck or fatiguing them. That's all in theory, however, since it depends Xyrella's battlecry remaining the same through the patch... so consider this fair warning if Xyrella once again does not function as written!