I had an absolute blast at #PTAKH playing an incredibly fun and extremely sweet deck of my own design. Let's start with my final decklist, just to get that out of the way, and then I'll go over how it came to be, what it does, why it has the cards it does, and how to play the major matchups.
So, the backstory:
At the Amonkhet Prerelease, I watched a player play a second Anointed Procession in a deck with several creatures with embalm, and the threat of suddenly making four creatures if any of his creatures died made things very awkward for his opponent (until she drew an Invocation Austere Command, but that card's not Standard-legal).
I was impressed by the power of multiplication and decided to try to build a deck around it.
My first attempt was just white and black because I like to always play as few colors as I can get away with. I had Start, which I think is actually a very good card (you're basically paying an extra mana on Raise the Alarm to draw a card; that's close to as good to a Ruinous Path that can only hit creatures), but there are actually not that many creatures you want to spend a lot of mana to kill at sorcery speed in this format.
Yahenni, Undying Partisan was pretty solid but considerably weaker than Catacomb Sifter, as well as a lot of speculative cards that I played one copy of just to try, like Bontu the Glorified and Oketra the True, both of which the deck can use very well. However, neither of them seemed like the best way to spend extra mana, and I didn't really need a big creature most of the time, though it's possible that they could be good in the deck. Especially Bontu, just because Gideon and Anointed Procession are stiff competition at four mana.
I liked the two-color version, but without Cryptolith Rite I found that it could be too slow to get everything onto the battlefield, and Catacomb Sifter is a great fit for the curve and power level of a deck that has a ton of great synergies. So I determined that the green was worth it, but it took me far too long to realize that I needed a 25th land to make everything work smoothly and that I could easily afford the extra land because all the scrying would still allow me to draw well in the mid game.
I played the deck on Magic Online a lot, and my major takeaway was that people really had no idea how to play against me. The reason is that when you're playing against me, my deck looks like a creature deck: I do a lot of attacking and blocking, and I'm playing Cryptolith Rite.
Traditionally, Cryptolith Rite decks are very weak against cards like Fumigate. Almost all of my opponents who had access to Fumigate brought it in against me. The problem is that I'm not actually a creature deck--I'm an enchantment deck. My engine happens to produce creatures, but the important part is the engine, not the creatures. If you kill the creatures, it only really sets me back a turn or two, but it doesn't interact with my actual strategy at all.
The other major failing on my opponents' part is not realizing that I have inevitability if they can't remove my enchantments. It doesn't matter how many Zombies they make with Diregraf Colossus or how many cards Cryptbreaker draws, and it doesn't matter how many Winding Constrictors they have to add extra counters to their walking Ballista.
If I have Cryptolith Rite, Hidden Stockpile, and Anointed Procession, I'll just draw Hidden Stockpile, Anointed Procession, Anointer Priest, or Gideon every turn, and I'll quickly get to the point where I'm gaining 16 or 32, or 64 life a turn while making around eight creatures a turn, and then I can flip Westvale Abbey or make a Gideon emblem and attack whenever I get far enough ahead, which will always happen eventually. After sideboarding, Dusk really punishes the other creature decks, like Zombies and B/G Energy, that try to build a big battlefield with me, because eventually I can just kill all of their creatures and attack.
Individual Card Choices
This one should be pretty clear, since it's basically a staple of most white decks in Standard, but it's doing a tremendous amount of work here. Obviously it's an early blocker while you're trying to set up, and it's a one-mana creature that you can tap for mana if you have Cryptolith Rite. The Clue is far more valuable here than in other places because of how it interacts with Hidden Stockpile and Anointed Procession.
Hidden Stockpile has a revolt trigger. Often, you'll have to sacrifice one your creatures to trigger revolt, but any time you can trigger it without sacrificing a creature, you can extend your board without needing multiple enchantments, which is a great way to get set up in the early game.
Anointed Procession doubles all tokens, not just token creatures, which means that it doubles Thraben Inspector's clues. This means that Thraben Inspector actually becomes a powerful card draw engine once your deck is firing on all cylinders, and eventually becomes your best card. In one round in the PT, I made eight Clues with a single Thraben Inspector, and used Cryptolith Rite to immediately sacrifice five of them.
This is the weakest card in the deck, but it serves some very important roles. First, it's just another one-drop to make sure your Cryptolith Rite can get you going as fast as possible, potentially allowing Gideon, Ally of Zendikar on turn 3, but it's most important for its interaction with Hidden Stockpile.
In the early game, you need to get your Hidden Stockpile going if you don't have a Clue or an Evolving Wilds, which means you'll often need to sacrifice a creature (or play Gideon, Ally of Zendikar and make an emblem). Sacred Cat allows you to do this very cheaply and it comes back immediately for very little mana to let you start going wide. Also, if you don't have Anointer Priest, but you have Anointed Procession, it can function as a backup lifegain engine to buy time.
It's most important against control decks. It's a cheap threat that's often not worth dealing with, which helps you put the pressure on. This is important because your goal is to force them to act so that you can resolve something important, but also, if you resolve Hidden Stockpile, which is plan A, they might try to stop you from using it by keeping your board empty; but the fact that Sacred Cat can give you a token even if they counter it makes it very hard for them to stop you from beginning to scry. Also, when your opponent plays a sweeper, it can shut down Hidden Stockpile even if you have multiples, and you'll need to find a way to get a creature or Evolving Wilds out to restart your engine. This makes it very important to try to keep a Sacred Cat in the graveyard so you can quickly rebuild in a way that gets around counterspells if your opponent plays a sweeper.
This is an absolute linchpin of the deck. Without Anointer Priest, you'd just die to fast starts or creatures with flying or trample. For a little more mana, this does everything Sacred Cat does, but more importantly, it gains massive amounts of life in the mid game. If you return it to the battlefield with two Anointed Processions in play, something I often try to set up, you immediately gain sixteen life. You'll also often have a Hidden Stockpile at that point, which will net you an extra sixteen life at the end of your turn. I often end games with around 70 life, and breaking a hundred isn't uncommon.
This is an all purpose player that really ties the room together. It's big enough to block usefully and threaten Planeswalkers, it doubles your scrying with Hidden Stockpile, or it gives you a backup scry engine if you don't have a Hidden Stockpile. It also lets you cast your four mana spells faster, since your fourth land often enters the battlefield tapped.
You're favored against everyone going long, so you need to buy time to get there. You can't let people keep Heart of Kiran or Cryptbreaker around. Also, you're by far the best deck at using Fatal Push, since you intend to trigger Revolt every turn anyway. It's extremely important to have a play that's this tempo positive to get away with taking a turn off and spending four mana to play an enchantment that will pay future dividends after playing a bunch of creatures that are too small to really impact the board.
This deck doesn't have Duskwatch Recruiter or any big spells, so it's easy to wonder how we can make use of this much mana. Don't worry. Between Hidden Stockpile, Westvale Abbey, and doubled Clue tokens, it's extremely easy to spend as much mana every turn as you can make. Once your engine gets rolling, you'll often want to sacrifice extra creatures in your upkeep to scry because finding an extra piece of your engine is so much better than drawing a land or Sacred Cat. You can afford to do a lot of that when the creatures can all pay to sacrifice themselves, and you'll still have mana left over to cast whatever you draw. It's also crucial to flipping Westvale Abbey quickly when you want to do that. Some of my best games have been games where I stuck on two lands but Cryptolith Rite allowed me to start going off. Then I just chose not to draw any more lands because making more creatures was a better way to get more mana.
This is the best card in the deck by far and I'm extremely reluctant to mulligan any hand with it. My favorite start is turn 2 Hidden Stockpile, turn 3 Hidden Stockpile, sacrifice Evolving Wilds, make two tokens, turn 4 Gideon, Ally of Zendikar, make an emblem, make two more tokens. Making tokens every turn and scrying regularly is the key that allows everything else to work.
It's great to have access to an answer this versatile when you can scry as often as this deck, so that if I absolutely have to answer something (Ulamog, the Ceaseless Hunger, for example), I can eventually. I originally had Cast Out, because I was very optimistic about the card in general, but this deck has too many important four-mana spells and not enough three-mana spells, so I found the cheaper casting cost to be more important the option to cycle, especially since this deck often doesn't care about three life.
The card the deck is built around. I was worried that four might be too many four-mana cards that don't always immediately impact the battlefield, but I knew I had to try four because they're so much more explosive in multiples. It just felt really weird choosing to play this card over Gideon, Ally of Zendikar, but it's definitely better in this deck. This is what lets you go over the top of everyone else who's trying to do big things.
This is a fantastic card that works particularly well with many other cards in the deck and provides an anthem effect for your tokens. I imagine the question "why only three?" is far more likely than, "Why is Gideon in this deck?" The answer is that because the creatures are so small, you're behind too often against other creature decks and they can just attack and kill Gideon or force you to block with enough creatures that you're not getting ahead; you can only play so many four-drops before the deck gets too clunky. Anointed Procession is more important.
The lands are pretty straightforward, Westvale Abbey is obviously fantastic in this deck in every possible way, and Evolving Wilds helps a lot with making the mana work in a three-color deck. It's also very important for triggering Revolt in his deck.
If your opponent knows how to play it, Mardu is one of your worst matchups because they can kill you before you get going, so you need to be able to kill Heart of Kiran and Toolcraft Exemplar every time. Against any aggressive creature deck, you want to board up to eight removal spells so that you can buy time to get all your pieces together.
This is just a win-the-game button against any midrange creature deck.
Your midrange value plan is so much more powerful than Aetherworks Marvel's Whirler Virtuoso plan that the only card you care about is Ulamog, the Ceaseless Hunger. Once you exile these, I really don't know how they can win if your draw is at all functional.
These come in against Aetherworks Marvel to answer Ulamog, the Ceaseless Hunger, Aetherworks Marvel, and against U/R control to answer Torrential Gearhulk or any smaller creature they side in, like Dragonmaster Outcast or Thing in the Ice. Because neither of those decks are really threatening your life total, it's safe to have a lot of these.
This is a super fun card for going long, but really, it should just be another Anguished Unmaking.
I mentioned that this isn't in the maindeck because it can be easy for other creature decks to attack it. If your opponent isn't playing many cheap creatures, it's still the best.
Talking Common Matchups
Fatal Push and Anointer Priest are more important here than usual. You'll probably need to slow them down to get your engine going before they kill you. This is a very bad matchup if your opponent knows to cut their removal and fill their deck with creatures and Planeswalkers, but in my testing against players on Magic Online and at the Pro Tour, people didn't figure that out. This is a huge part of the reason that I chose to play this deck at the Pro Tour: Mardu is a good matchup if your opponent leaves in their removal and adds Fumigate, and I expected that even at the Pro Tour, most of my opponents would make that mistake. Unfortunately, now that I've written this, your best chance is to hope your Mardu opponent wasn't interested in reading about tokens.
Ideally, cast Lost Legacy and name Ulamog, then just make as many creatures as you can. If you don't draw Lost Legacy, try to use your scrys to fill your hand with Anguished Unmakings so that you can exile their Aetherworks Marvels and Ulamogs. When you sideboard, you can safely cut Sacred Cat--you shouldn't think of yourself as the aggro deck. You're not really trying to race them; you're trying to invalidate their end game and trump them with yours.
Your goal is to resolve Hidden Stockpile, Gideon, Ally of Zendikar, or Anointed Procession. Westvale Abbey is one of your best cards. Be careful about when you cast your important spells. Don't run into Censor if you can help it, don't cast a spell you care about when they have exactly three mana. Wait until they have four so that they have to take a turn off casting Glimmer of Genius in order to counter it. Don't cast an expensive spell into six mana to let them resolve Torrential Gearhulk without risk. If you can't stick a reasonable engine, they have inevitability, and their card draw will beat you because very few of your cards matter and they can counter them. If you can get a couple enchantments down, they can draw all the cards they want; your 1/1s will be relentless and they can't really stop you or kill you once you get going. Be very careful with Westvale Abbey. Don't run it into Disallow or Commit. You want to primarily use it to make tokens.
Kill Cryptbreaker and Diregraf Colossus. Hope they draw Metallic Mimic and Lord of the Accursed so that Dusk kills all their creatures. Pressure their life total where you can to try to pinch Cryptbreaker draws and make it harder for them to attack for fear of dying to a counterattack. Their creatures are much bigger than yours. You'll have to chump block a lot. That's fine, you can make more creatures than them at most stages of the game, and as long as you make it past the early game, you'll probably win whenever you resolve a big Dusk.
This deck loses a lot of its strength once it's a known entity, as my decks so often do, but I think my plans against Zombies, Marvel, and every midrange creature deck are very solid and robust. I've done very well against all but the best U/R Control players, so I think the deck might have some legs to it, and either way, if you like doing crazy things, this is absolutely a deck you should try, as the battlefield in the games you win often get extremely crazy.