Overview

Uldaros Theorix is the Dimir elder sphinx of Hexhaven. It is a six-mana 5/5 flier with a single, very large enter trigger: when you cast it, it exiles up to one nonland card of each card type from your graveyard, copies them, and lets you cast any number of those copies with a combined mana value of 6 or less for free. Permanent copies enter as tokens. The card types that count are artifact, creature, enchantment, instant, sorcery, planeswalker, battle, and kindred, so a well-stocked graveyard offers a menu of options, and the six-point mana value budget decides how many you can take.

The budget is where this list gets its edge. Cards with suspend and no mana cost have a mana value of 0, so their copies cost nothing from the budget. Ancestral Vision draws three, Inevitable Betrayal takes the best creature from an opponent's library, Profane Tutor finds any card, and Lotus Bloom and Sol Talisman become mana rocks, all without spending any of the six points. A single trigger that copies Inevitable Betrayal, Lotus Bloom, a two-mana creature such as Thassa's Oracle, and a four-mana instant such as Gifts Ungiven is four free spells from one commander cast.

The rest of the deck fills the graveyard with the right mix before Uldaros resolves, and finds ways to get the trigger more than once. The self-mill package (Stitcher's Supplier, Hedron Crab, Millikin, Deranged Assistant, Mesmeric Orb, Glimpse the Unthinkable) does the bulk of the work, while Entomb, Unmarked Grave, and Buried Alive place specific cards. Because the trigger only works when you cast Uldaros, flicker effects do nothing; the deck re-casts it instead. Snap and Otawara, Soaring City return Uldaros to hand, and a clone you cast that enters as a copy of Uldaros was itself cast, so its copy of the trigger works too. Spark Double and Sakashima of a Thousand Faces avoid the legend rule entirely. Panharmonicon and Starfield Vocalist make each Uldaros trigger happen twice, provided the graveyard holds a second target of each type.

The Engine: Uldaros + Syr Konrad, the Grim

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Synergy Spotlight
Uldaros Theorix + Syr Konrad, the Grim
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Uldaros Theorix Uldaros Theorix
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Syr Konrad, the Grim Syr Konrad, the Grim

Syr Konrad, the Grim deals 1 damage to each opponent whenever another creature dies, whenever a creature card is put into a graveyard from anywhere other than the battlefield, and whenever a creature card leaves your graveyard. This deck triggers all three constantly. Every creature card milled by Stitcher's Supplier, Hedron Crab, or Glimpse the Unthinkable is a ping to each opponent, and Konrad counts creature cards milled from opponents' libraries too, since that clause covers any graveyard. Konrad's own {1}{B} ability makes each player mill a card, which feeds the graveyard and can trigger Konrad again.

Uldaros adds the third trigger. When Uldaros exiles a creature card from your graveyard to copy it, that card leaves your graveyard and Konrad deals 1 damage to each opponent. Reanimate, Animate Dead, and Superior Spider-Man do the same. Ancient Cellarspawn adds a separate drain on top: whenever you cast a spell for less mana than its mana value, target opponent loses life equal to the difference. Every copy Uldaros lets you cast is cast for zero, so a trigger that casts six mana value of spells drains an opponent for six on its own.

Panharmonicon and Starfield Vocalist double the whole package. Uldaros entering triggers twice, so with two targets of each card type in the graveyard, it exiles and copies two sets and grants two separate six-point budgets. Each copied creature that enters as a token also has its enter triggers doubled: a token copy of Stitcher's Supplier mills six instead of three, and a token copy of Thassa's Oracle checks your library twice.

Result: With Uldaros, Syr Konrad, and a stocked graveyard, a single cast of the commander replays a spread of spells for free, pings each opponent for every creature card it exiles, and refills the graveyard for the next cast. With Ancient Cellarspawn in play the free casts also drain an opponent directly, and with Panharmonicon or Starfield Vocalist the entire trigger happens twice.

Key Cards

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Thassa's Oracle
Primary Win Condition · Devotion Finisher
When it enters, look at the top X cards of your library, where X is your devotion to blue, and put up to one on top and the rest on the bottom. If X is greater than or equal to the number of cards in your library, you win the game. Uldaros can cast a token copy of it from the graveyard for two of its six points, which means the Oracle only has to be milled, not drawn: once the library is small enough, casting Uldaros ends the game. Mesmeric Orb, Hedron Crab, Glimpse the Unthinkable, and Singularity Rupture shrink the library quickly, and a low devotion count is enough once only a few cards remain.
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Mesmeric Orb
Self-Mill Engine · Passive Mill
Whenever a permanent becomes untapped, that permanent's controller mills a card. Every land, mana rock, and creature you untap each turn mills you one card, so the Orb puts five to ten cards into your graveyard every turn cycle with no further mana investment. Opponents mill themselves the same way when their permanents untap, which feeds Syr Konrad whenever creature cards hit their graveyards. The risk is decking yourself, so the Orb is best deployed when Thassa's Oracle, Laboratory Maniac, or Jace, Wielder of Mysteries is ready to close.
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Laboratory Maniac
Alternate Win Condition · Empty Library
If you would draw a card while your library has no cards in it, you win the game instead. Laboratory Maniac backs up Thassa's Oracle: if the Oracle is countered or exiled, the Maniac wins from any draw with an empty library, and Consider, Careful Study, Frantic Search, and Windfall all provide that draw. Jace, Wielder of Mysteries is a third copy of the effect, and because Jace is a planeswalker, it is also one of the card types Uldaros can copy and cast from the graveyard.
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Panharmonicon
ETB Doubler · Token Amplifier
If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time. Uldaros is a creature, so its own enter trigger fires twice: with a second target of each card type in the graveyard, you exile and copy two sets and get two separate six-point budgets. Every creature copied as a token gets the same treatment, so Stitcher's Supplier mills six on entry and Thassa's Oracle checks the library twice. Starfield Vocalist provides the same effect on a creature body.

Playing the Deck

The early game is about mana and graveyard setup. Sol Ring, Arcane Signet, Talisman of Dominance, Fellwar Stone, and Mind Stone ramp toward a turn-four or turn-five Uldaros, and Lotus Bloom and Sol Talisman can be suspended early for zero and one mana respectively. Stitcher's Supplier mills three on entering and three more on dying, Hedron Crab mills three for each land drop, and Millikin and Deranged Assistant mill a card each time they tap for mana. The target before Uldaros arrives is variety rather than volume: an artifact, a creature, an instant, and a sorcery in the graveyard make the first cast worth several spells. Entomb, Unmarked Grave, and Buried Alive let you choose the exact cards, and Entomb works at instant speed at the end of an opponent's turn.

Buried Alive is strongest when it sets up both halves of the plan at once. Put Syr Konrad, Thassa's Oracle, and a cheap value creature into the graveyard: Konrad can come back with Reanimate or Animate Dead, and the Oracle waits as an Uldaros win condition. Gifts Ungiven works similarly at instant speed, since whichever two cards the opponent sends to the graveyard become Uldaros options. The suspend cards deserve special attention: Ancestral Vision, Inevitable Betrayal, and Profane Tutor are slow from hand because they must wait on suspend, so milling them is often the best outcome, because Uldaros casts their copies for none of its budget.

The mid-game is about getting the trigger more than once. Snap and Otawara, Soaring City return Uldaros to hand for another cast, and Otawara's channel cost drops by one for each legendary creature you control. Clones you cast that copy Uldaros count as cast, so their trigger works; Spark Double and Sakashima of a Thousand Faces avoid the legend rule and keep both bodies. The command zone is a fallback too: if Uldaros dies, recasting it from the command zone gives a fresh trigger at a higher cost. Vohar, Vodalian Desecrator can be sacrificed to cast an instant or sorcery from the graveyard, and The Ancient One loots, mills, and becomes an 8/8 attacker once your graveyard holds eight permanent cards.

The end game has three routes: an empty or near-empty library for Thassa's Oracle, Laboratory Maniac, or Jace; Syr Konrad and Ancient Cellarspawn damage from milling and free casts; or combat with the 5/5 flier and whatever Inevitable Betrayal stole. Glimpse the Unthinkable mills ten, Singularity Rupture destroys all creatures and mills half the library of any number of target players, including you, and Windfall makes every player discard and redraw, which wins on the spot with Laboratory Maniac or Jace and an empty library. Ancestral Vision refuels the hand, and Inevitable Betrayal takes an opponent's best creature, either off suspend or for free through Uldaros.

Strengths & Weaknesses

Strengths: Uldaros turns the graveyard into a second hand: every card that gets milled is a potential free spell later, so self-mill is card advantage rather than a cost. Zero-mana-value suspend cards let one trigger deliver far more than six mana of value. The deck plays toward three win conditions (empty library, Syr Konrad damage, combat) that do not depend on each other. Bounce, clones, and the command zone give it several ways to reuse the enter trigger, and Panharmonicon and Starfield Vocalist double it. Dimir's instant-speed tools (Snap, Entomb, Gifts Ungiven, Frantic Search) let the deck set up the graveyard on opponents' end steps and enter its own turn ready to cast Uldaros.

Weaknesses: The deck is heavily graveyard-dependent. A resolved Rest in Peace, Leyline of the Void, or Tormod's Crypt empties the menu Uldaros draws from and turns the commander into a six-mana 5/5 flier. The trigger only works when Uldaros is cast, so flicker, reanimation, and cheating it into play do nothing, and each recast from the command zone costs two more mana. The library is the resource, and over-milling without a win condition ready is a real failure mode. The deck runs very few counterspells and relies on speed rather than interaction, making it vulnerable to targeted disruption before the win condition lands.

Verdict
Uldaros Theorix is a six-mana commander that turns a Dimir self-mill graveyard into a second hand. Each cast copies up to one card of each type and replays up to six mana value of them for free, and the zero-cost suspend cards in this list push that well past six mana of real value. The deck's job is to fill the graveyard with the right mix and to cast Uldaros more than once, through bounce, clones, and the command zone. It converges on three win conditions: Thassa's Oracle or Laboratory Maniac with an empty library, Syr Konrad and Ancient Cellarspawn damage from milling and free casts, and combat with a flier backed by stolen threats. It is slower to set up than the other Hexhaven sphinxes, which may explain its low deck count, but a single well-prepared cast can swing a game on its own.

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Full Decklist

The full 100-card Uldaros Theorix Commander deck, enriched with current prices. Click any card to expand it.

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