The planar bridge is open, and Bolas has set up his citadel on Ravnica.

Bolas's Citadel

That’s an extremely powerful set of abilities. Let’s break them down one-by-one.

You may look at the top card of your library any time. You may play the top card of your library.

As Experimental Frenzy and Future Sight have shown, this represents a powerful engine. You will eventually get stuck once you hit a second land, but you will typically still draw 3 extra cards every turn (barring deck manipulation). The underlying math is described by the negative hypergeometric distribution, which I applied to Experimental Frenzy in this article.

If you cast a spell this way, pay life equal to its converted mana cost rather than pay its mana cost.

As history has shown, paying life instead of mana is completely broken. The Channel half of this website’s iconic combo is banned in Legacy, and Phyrexian mana spells are either banned (Gitaxian Probe and Mental Misstep) in Modern or among the most-played spells in the format (Surgical Extraction and Dismember).

So whenever a card allows you to transform life into mana, we’d better pay attention, especially when it’s a one-for-one exchange that can pay for colored mana as well.

Tap, sacrifice ten nonland permanents: Each opponent loses 10 life.

This is only icing on the cake, but it could act as a win condition once you’ve basically drawn your entire deck and control 20 nonland permanents. To accomplish this, you need to cast another Bolas’s Citadel from the top of your library, hold priority, respond by sacrificing the original Citadel and 9 other permanents, and seal the deal with the second copy of the legendary artifact.

How to break Bolas’s Citadel?

Well, the dream is to win the same turn you slam it. This brings back memories of another broken 6 mana enchantment: Yawgmoth’s Bargain. It enabled one of the many combo decks in the late 1990’s. For a nice historical perspective, I recommend this article.

In Modern, a Bolas’s Citadel combo deck could be constructed with Lotus Bloom and Aetherflux Reservoir. In older formats, you could even add Sensei’s Divining Top. But I fear Bolas’s Citadel may be slightly too slow for the non-rotating formats, so let’s start brewing in Standard. To win the turn Bolas’s Citadel comes down, a deck needs several ingredients.

Life Gain Spells

If you keep paying life to cast spells, eventually you’re going to run out. The following list contains Standard cards that at least break even on life, either by gaining life immediately or possibly later in the same turn. (I excluded overly situational cards, such as life gain effects that require prior creatures or creatures that die. Other notable exclusions are Sanguine Sacrament, which doesn’t work because X must be 0 according to rule 107.3c, and Angel of Grace, which does not prevent loss of life.)

Interplanar BeaconPlaza of HarmonyAjani's WelcomeHealing GraceNightmare's ThirstVicious RumorsNavigator's CompassDiamond MareHighland GameImpassioned OratorMoment of CravingPendulum of Patterns - Planeswalker Deck Exclusives (Aether Revolt)RevitalizeSovereign's BiteWildgrowth WalkerCentaur PeacemakerGift of ParadiseInspiring ClericKnight of AutumnOrazca RelicRitual of RejuvenationShield MareDepose // DeployPelakka WurmArchway AngelRevival // Revenge

The most appealing cards from this group are:

Go Past Land Gluts

Even if you put enough life gain effects in your deck, Bolas’s Citadel doesn’t allow you to just flip your deck onto the table. Eventually, you will hit a second land and get stuck. But there are ways around this. Most notably: effects that manipulate the top of your library, thin out lands from your deck, and/or grant additional land drops. Non-land mana sources that enable a lower land count also boost consistency. Here is a non-exhaustive list:

Evolving WildsMox AmberLlanowar ElvesEnter the UnknownArtificer's AssistantOpen the GatesWand of VertebraeDiscovery // DispersalDrowned SecretsTreasure Map // Treasure CoveOrazca RelicJadelight RangerWayward SwordtoothRiverwise AugurPath of DiscoveryJace, Wielder of MysteriesScapeshiftDoom Whisperer

Several cards stand out:

You can see a deck taking shape here.

Explore Citadel Combo

4 Overgrown Tomb
3 Simic Guildgate
1 Dimir Guildgate
4 Plaza of Harmony
4 Golgari Guildgate
3 Forest
1 Swamp
2 Llanowar Elves
4 Wildgrowth Walker
4 Jadelight Ranger
4 Merfolk Branchwalker
2 Hydroid Krasis
4 Bolas's Citadel
2 Mastermind's Acquisition
4 Gift of Paradise
4 Orazca Relic
4 Open the Gates
3 Scapeshift
3 Depose/Deploy

Sideboard
4 Duress
1 Chance for Glory
1 Vivien Reid
1 Memorial of Folly
1 Assassin’s Trophy
1 Nezahal, Primal Tide
1 Find/Finality
1 Hostage Taker
1 Root Snare
1 Fungal Infection
1 Cry of the Carnarium
1 Kraul Harpooner

This looks like a Sultai Midrange list, with Bolas’s Citadel and several support cards thrown in. It can hold off aggro decks with Wildgrowth Walker and Jadelight Ranger, ramp into a turn 5 Bolas’s Citadel, and typically win on turn 6. After thinning your deck with Scapeshift, you can easily accrue 20 power worth of creatures, wish for Chance of Glory (castable via Gift of Paradise) and attack for the win. Or, if you manage to thin all lands out of your deck, just activate Bolas’s Citadel twice.

Post-board, you have the opportunity of adding Duress against countermagic or the ability to transform into a less combo-reliant midrange deck that evades the hate cards your opponents might board. In this way, the deck reminds me of Greater Gifts.

But we can go deeper. Want see a list that is really out there?

Artifact Citadel Combo

4 Plaza of Harmony
2 Breeding Pool
1 Overgrown Tomb
4 Golgari Guildgate
4 Simic Guildgate
1 Dimir Guildgate
1 Forest
1 Island
1 Swamp
3 Sai, Master Thopterist
3 Fblthp, the Lost
4 Bolas's Citadel
2 The Antiquities War
4 Orazca Relic
4 Gift of Paradise
4 Depose/Deploy
3 Wand of Vertebrae
4 Open the Gates
4 Navigator's Compass
3 Scapeshift
3 Mox Amber

Sideboard
4 Duress
3 Treasure Map/Treasure Cove
2 Karn, Scion of Urza
2 Zahid, Djinn of the Lamp
2 Sailor of Means
2 Assassin's Trophy

Bolas’s Citadel is an artifact, so Sai, Master Thopterist and The Antiquities War fit well. They also generate large armies for Deploy.

Once you have this artifact-synergy base already, it makes sense to add Navigator’s Compass for life gain, Wand of Vertebrae to mill lands, and Mox Amber to ramp. As an additional way to turn on Mox Amber, we have Fblthp, the Lost, which even draws two cards when you cast it from your library.

The deck might look terrible at first glance, but I’ve been goldfishing it, and I assure you that it can generate turn 5 kills surprisingly often. Hugo de Jong is the driving force behind both brews, with relevant contributions from Danny de Rooij, Tom Theijssen, Jesper Box, and myself. We’re still early in the brewing process, but we’re confident that Bolas’s Citadel has the potential to be a powerhouse combo engine in Standard.

I, for one, welcome our new Dragon-God overlord and have already set this video as my phone’s lock screen wallpaper in his honor.