Those legacy aficionados among you may have heard of Four Horsemen: an old legacy deck that came into the limelight after Jeff Liu took 17th place with it at an SCG invitational back in 2012. However, that same deck suffered from a fairly serious fault: the official magic rulings regarding loops and slow play require that a player be able to state, at least in theory, how many times a particular loop will be executed in order for the shortcut to be valid. The mechanics of the original Four Horsemen (details in the article) meant that this wasn't possible: the required gamestate at the end of the loop was probabilistic, not deterministic, and as such executing the combo would typically result in what was technically slow play by the Horsemen player.
After much tinkering with the deck I managed to produce something that felt similar to the original Four Horsemen without requiring the pilot to commit rules infractions in order to execute their combo.
The Combo(s):
Mesmeric Orb
+
Basalt Monolith
: This is engine that powers the deck. As with the original list, these two artifacts allow you to instantly dump your entire library into your graveyard.
Narcomoeba
: The payoff for dumping your entire library into your graveyard is four of these bad boys.
Dread Return
: Turn those Narcomoebae into something more game-winning.
Laboratory Maniac
: The most straightforward way to win is to reanimate this dude.
Think Twice
: Wins the game alongside Laboratory Maniac once your entire library is in your graveyard. Note that the combo typically ends with you having an untapped Basalt Monolith, and as such only a single blue source is needed to flashback Think Twice and win the game.
Sharuum the Hegemon
: Sometimes you don't have one spare blue source. A pair of Sharuums form the alternate win condition for this deck: reanimate Sharuum with Dread Return, then use the trigger on Sharuum to reanimate the other Sharuum. The legend rule will kill off your first Sharuum before the trigger from the second one entering is put on the stack, which means that the second Sharuum can reanimate the first. Loop for an arbitrarily large number of iterations.
Bridge from Below
: With Bridge in your graveyard, each Sharuum death will produce a 2/2 zombie, giving you as many as you want.
Akroma's Memorial
: Those zombies need to attack this turn, so the final Sharuum's enters the battlefield trigger should renaimate Akroma's Memorial to give your zombie army haste.
The Supporting Cast:
Academy Ruins
: Can reclaim both halves of your combo that you might actually need to cast. The upside of Mesmeric Orb with Academy Ruins is that you might mill into a combo piece that you can reclaim. The downside is that you can't end-of-opponent's-turn activate Academy Ruins for a combo piece if you already have Mesmeric Orb in play, because the card will just get milled off the top again when you untap.
Ancient Tomb
: Fast mana. Especially good given that both of your combo pieces are artifacts. The other land choices are fairly obvious I hope.
Brainstorm
: Card selection and hand-attack protection. One notable interaction is that Mesmeric Orb can mill off whatever you put on top of your library.
Cabal Therapy
: A good way of checking that the coast is clear when trying to combo off. Once you've milled over your entire library, you can sacrifice Narcomoebae for the flashback to strip any problematic cards from your opponent's hand. In this case, Bridge from Below will replace the Narcomoebae with zombies, so you'll still have enough creatures to cast Dread Return. Also notable that you can target yourself to get cards like Sharuum into the graveyard should you happen to draw them.
Force of Will
: You aren't typically going to be flush with mana, and Force both denies your opponent from doing degenerate things and protects your combo. If you only need to protect your own combo then
Pact of Negation
would actually be better, so perhaps some number of these Forces should be Pacts.
Lim-Dul's Vault
: An odd card, but an excellent tutor. The life loss is typically negligible, but sufficient life payment and clever card ordering can often eventually find you a pile of five cards with both artifact combo pieces in it. The important thing to note is the order in which you're putting cards on the bottom of your library, and which of those cards will see which other cards from previous and subsequent piles that you put on the bottom (a fact determined by the number of cards in your library when you cast Lim-Dul's Vault. For example, if you have 46 cards, then one complete cycle through your library will result in the last of those 46 being drawn into a new pile of five along with the top four of the first pile that you saw).
Ponder
: Card selection in a combo deck.
Thoughtseize
: Clears the way for your combo. Disrupts your opponent's plan, and makes your first Cabal Therapy much less of a guessing game.
