Thassa's OracleThassa's Oracle | Art by Jesper Ejsing

Love it or hate it, Thassa's OracleThassa's Oracle is all over the place in cEDH. The de-facto closer for any deck that can run it (and that's a lot, considering how prominent blue is), Thassa's Oracle is a cost-effective, sure-fire way to win the game.

So, how would things change if this Merfolk got axed? Let's take a trip - to cEDH without Thassa's Oracle.

Thassa's OracleThassa's Oracle: The Card

First off, let's talk break down the card itself: what Thassa's Oracle does, and how it does it.

For , Thassa's Oracle is a 1/3 Merfolk Wizard that, when it enters, causes you to look at the top X cards of your library, where X is your devotion to blue (your devotion to blue is equal to the number of pips among mana costs of permanents you control). Put up to one of them on the top of your library, then put the rest of them on the bottom of your library in a random order.

If X is greater than or equal to the number of cards in your library, you win the game. For cEDH, it's that last bit that matters; Thassa's Oracle wins the game if you have an empty (or nearly empty) library.

Emptying out a library is a trivially easy task in cEDH. Whether it be funneling infinite mana into Thrasios, Triton HeroThrasios, Triton Hero activations or simply resolving a Demonic ConsultationDemonic Consultation in a properly-constructed deck, there are plenty of ways to do it across all colors.

It's because of that ease, and Thassa's Oracle's reasonably low cost, that the card is so ubiquitous. However, don't misconstrue the role of the card for the text of the card; in a vacuum, Thassa's Oracle is quite bad.

From one broken two-drop to the next.

Think, for a moment, to one of cEDH's other game-winning two-drops: Underworld BreachUnderworld Breach. For , this card is infinitely more useful than Thassa's Oracle, allowing you a full turn's worth of access to your graveyard. If Thassa's Oracle is in hand with a full library, the card is functionally useless.

No one in cEDH is paying to have a worse version of scry 2. Plenty of players, however, will pay , if only to start churning through repeat tutors and rituals. In and of itself, Thassa's Oracle does nothing. Underworld Breach, on the other hand, is a can opener for your graveyard, turning previously-cast tutors into victories at just about any point in the game.

Two Types of Combos

So, now that we understand that Thassa's Oracle is a "bad card," the likes of which only survive in cEDH because of their broken exploits at crux moments, let's go back to the combos that give rise to such crux moments. By and large, this falls into two categories - Thassa's Oracle-dependent and Thassa's Oracle-independent.

In the dependent camp, we have the most readily shoehorned-in combo across all of cEDH: Tainted Fish. This combo consists of Thassa's Oracle and either of Tainted PactTainted Pact or Demonic ConsultationDemonic Consultation. Resolve Thassa's Oracle, hold priority in response to the enters trigger, cast either of the latter two spells, empty out your library, and huzzah! You've won the game once the trigger resolves.

While other cards could conceivably play the role of Thassa's Oracle here, such as Jace, Wielder of Mysteries, these substitutions make the combo far clunkier and astronomically more mana intensive (in cEDH terms). As such, the efficiency of Thassa's Oracle is the key factor contributing to the combo's ubiquity.

Take out Thassa's Oracle, and the combo largely falls off.

In the independent camp, we return to the Izzet branch of Underworld BreachUnderworld Breach lines, particularly Brain FreezeBrain Freeze and Lion's Eye DiamondLion's Eye Diamond. Through this combination, the repeat casting of Lion's Eye Diamond and Brain Freeze from the graveyard while Underworld Breach is in play allows for its controller to put their entire deck into their graveyard (minus a select few cards pitched into exile to pay for escape costs), eventually escaping Thassa's Oracle as a closer.

This line is independent of Thassa's Oracle, however, because it can ultimately be closed a bunch of different, relatively as-easy ways. Once the storm count gets large enough, for example, the Underworld Breach player can simply cast Brain Freeze to mill out their opponents, thus winning once each other player has attempted to draw a card. Sure, Thassa's Oracle slots in as a nice way to win that same turn (something which really matters in tournaments with last-turn extra time rules), but this is far from the only way to make Underworld Breach lethal.

The Best Blue Decks

So, now that we know that there are two types of combos using Thassa's Oracle - those with or without easy replacement for the card - how would its absence shake up the format? To understand that, let's compare some of the best blue decks in cEDH to the broader arena of brews.

Blue Farm

Starting us off is cEDH's boogeyman and the king of midrange: Blue Farm. This deck is minimally dependent on its commanders yet simultaneously capable of maximal benefit; each is a notable card advantage engine in its own right, and combined they allow for consistent card draw across the game.

Whether it's your opponents simply casting spells or you finding a combat opening with something as simple as an Esper SentinelEsper Sentinel, these guys will guarantee an extra card here and there for as long as the game goes on.

Most importantly, however, these two grant access to the ultimate toolkit for cEDH. Underworld BreachUnderworld Breach, Rhystic StudyRhystic Study, Smothering TitheSmothering Tithe, NecropotenceNecropotence - playing Blue Farm is about playing the best cards in the format.

Speaking of best cards, Blue Farm of course runs the aforementioned Tainted Fish package as a cost-effective and compact way to close out games, but - as a deck that runs Underworld Breach and Brain Freeze - it really isn't confined to Thassa's Oracle. As such, taking away this Merfolk doesn't really do much to the deck.

Sure, it becomes more susceptible to graveyard hate, but all in all Blue Farm couldn't really care less. Good decks stay good.

RogSi

Speaking of good decks that stay good, let's talk about the premier turbo deck in cEDH: RogSi. By running the zero-mana Rograkh as its real commander of choice (poor old Silas is just here for the Dimir color identity addition), this turbo deck is able to supercharge its mana production and early-game interaction capabilities. Culling the WeakCulling the Weak, Mox AmberMox Amber, and Fierce GuardianshipFierce Guardianship are all live as early as turn one, every game.

So, what does this deck do to win? Well, like Blue Farm before it, RogSi runs both Tainted Fish and Izzet Underworld Breach lines as packages to close out the game. Cut one, and the other line remains unbothered.

Kinnan

Finally, Kinnan, the other best blue deck in the format and the simplest to evaluate. This deck crushes its opponents through infinite mana and absurd creatures flipped into play off its activated ability. What it doesn't use to win the game is Thassa's Oracle. That's right, Kinnan might not be playing Underworld Breach, but red isn't the only other way to win the game in this format.

Whether it be looping Cephalid ColiseumCephalid Coliseum to force its opponents to deck themselves or simply stampeding through after an infinitely large Finale of DevastationFinale of Devastation has resolved, this blue deck would be all-around better off if Thassa's Oracle was banned.

And All the Rest

Looking more broadly, it's here that things really start to get a bit dim if Thassa's Oracle were to be removed. Like Dockside ExtortionistDockside Extortionist before it, a bevy of decks exist in cEDH that are dedicated to unique lines which end with an empty library. The Master of KeysThe Master of Keys and its escaping of Animate DeadAnimate Dead, Glarb, Calamity's AugurGlarb, Calamity's Augur and a cracked DoomsdayDoomsday pile, Urza and a good-ol'-fashioned PolymorphPolymorph line.

Suffice it to say, Thassa's Oracle may be ubiquitous across cEDH, but for many of the lower-powered blue decks out there it's more of a life line than most would immediately recognize. Unlike the first three decks, the question here isn't "How much better is this deck because of Thassa's Oracle?" but rather "How much does this deck need Thassa's Oracle?"

Wrap Up

At the end of the day, no matter how bad of a card Thassa's Oracle is on its own, the card is everywhere. The problem, however, is that it isn't really a source of meaningful power for the best cEDH decks in the format; at least, not in a way that uniquely benefits them.

Take Thassa's Oracle away and all that really ends up happening is a widening of the gap between the decks that benefited from the card and those that rely on it. Sure, Blue Farm and RogSi will get weaker, but how much stronger do we really want Kinnan to be, and how many home brews are we fine with seeing disappear as a result?

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