It's for the best that they banned Agent of Treachery last week. This is our M21 preview card:

Here's what I had written about Transmogrify before last Monday:

* * *

It would be pretty bonkers if they reprinted Polymorph in Core Set 2021.

Here is the best deck in Standard:

Magic: The Gathering TCG Deck - Jeskai Lukka (Yorion) by Matteo Falconetti

'Jeskai Lukka (Yorion)' - constructed deck list and prices for the Magic: The Gathering Trading Card Game from TCGplayer Infinite!

Created By: Matteo Falconetti

Event: Red Bull Untapped International Qualifier - 5/16/20

Rank: 1

Standard

Market Price: $286.50

Cards

Omen of the Sun

Color Identity:W

Market Price: $0.10

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/206784_200w.jpg

Flash
When Omen of the Sun enters the battlefield, create two 1/1 white Human Soldier creature tokens and you gain 2 life.
{2}{W}, Sacrifice Omen of the Sun: Scry 2.

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Dream Trawler

Color Identity:U,W

Market Price: $0.62

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/207050_200w.jpg

Flying, lifelink
Whenever you draw a card, Dream Trawler gets +1/+0 until end of turn.
Whenever Dream Trawler attacks, draw a card.
Discard a card: Dream Trawler gains hexproof until end of turn. Tap it.

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Lukka, Coppercoat Outcast

Color Identity:R

Market Price: $2.09

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/211996_200w.jpg

+1: Exile the top three cards of your library. Creature cards exiled this way gain "You may cast this card from exile as long as you control a Lukka planeswalker."
−2: Exile target creature you control, then reveal cards from the top of your library until you reveal a creature card with higher converted mana cost. Put that card onto the battlefield and the rest on the bottom of your library in a random order.
−7: Each creature you control deals damage equal to its power to each opponent.

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Castle Vantress

Color Identity:U

Market Price: $0.53

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/199284_200w.jpg

Castle Vantress enters the battlefield tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

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Glass Casket

Color Identity:W

Market Price: $0.14

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/199004_200w.jpg

When Glass Casket enters the battlefield, exile target creature an opponent controls with converted mana cost 3 or less until Glass Casket leaves the battlefield.

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Fires of Invention

Color Identity:R

Market Price: $0.23

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/199255_200w.jpg

You can cast spells only during your turn and you can cast no more than two spells each turn.
You may cast spells with converted mana cost less than or equal to the number of lands you control without paying their mana costs.

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Hallowed Fountain

Color Identity:U,W

Market Price: $5.71

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/182831_200w.jpg

({T}: Add {W} or {U}.)
As Hallowed Fountain enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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Yorion, Sky Nomad

Color Identity:U,W

Market Price: $1.34

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/212715_200w.jpg

Companion — Your starting deck contains at least twenty cards more than the minimum deck size. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} any time you could cast a sorcery.)
Flying
When Yorion enters the battlefield, exile any number of other nonland permanents you own and control. Return those cards to the battlefield at the beginning of the next end step.

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Agent of Treachery

Color Identity:U

Market Price: $5.33

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/192629_200w.jpg

When Agent of Treachery enters the battlefield, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

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The Birth of Meletis

Color Identity:W

Market Price: $0.47

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/206752_200w.jpg

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Search your library for a basic Plains card, reveal it, put it into your hand, then shuffle your library.
II — Create a 0/4 colorless Wall artifact creature token with defender.
III — You gain 2 life.

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Narset, Parter of Veils

Color Identity:U

Market Price: $0.89

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/188705_200w.jpg

Each opponent can't draw more than one card each turn.
−2: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

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Island

Color Identity:U

Market Price: $0.21

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/227281_200w.jpg

({T}: Add {U}.)

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Dovin's Veto

Color Identity:U,W

Market Price: $1.22

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/187186_200w.jpg

This spell can't be countered.
Counter target noncreature spell.

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Shark Typhoon

Color Identity:U

Market Price: $12.11

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/212133_200w.jpg

Whenever you cast a noncreature spell, create an X/X blue Shark creature token with flying, where X is that spell's converted mana cost.
Cycling {X}{1}{U} ({X}{1}{U}, Discard this card: Draw a card.)
When you cycle Shark Typhoon, create an X/X blue Shark creature token with flying.

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Temple of Epiphany

Color Identity:R,U

Market Price: $0.40

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/215545_200w.jpg

Temple of Epiphany enters the battlefield tapped.
When Temple of Epiphany enters the battlefield, scry 1.
{T}: Add {U} or {R}.

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Sacred Foundry

Color Identity:R,W

Market Price: $11.36

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/175200_200w.jpg

({T}: Add {R} or {W}.)
As Sacred Foundry enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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Plains

Color Identity:W

Market Price: $0.18

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/227283_200w.jpg

({T}: Add {W}.)

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Teferi, Time Raveler

Color Identity:U,W

Market Price: $9.94

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/187194_200w.jpg

Each opponent can cast spells only any time they could cast a sorcery.
+1: Until your next turn, you may cast sorcery spells as though they had flash.
−3: Return up to one target artifact, creature, or enchantment to its owner's hand. Draw a card.

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Elspeth Conquers Death

Color Identity:W

Market Price: $1.89

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/207052_200w.jpg

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Exile target permanent an opponent controls with converted mana cost 3 or greater.
II — Noncreature spells your opponents cast cost {2} more to cast until your next turn.
III — Return target creature or planeswalker card from your graveyard to the battlefield. Put a +1/+1 counter or a loyalty counter on it.

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Raugrin Triome

Color Identity:R,U,W

Market Price: $6.49

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/212695_200w.jpg

({T}: Add {U}, {R}, or {W}.)
Raugrin Triome enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

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The Wanderer

Color Identity:W

Market Price: $0.39

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/187200_200w.jpg

Prevent all noncombat damage that would be dealt to you and other permanents you control.
−2: Exile target creature with power 4 or greater.

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Shatter the Sky

Color Identity:W

Market Price: $0.94

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/207069_200w.jpg

Each player who controls a creature with power 4 or greater draws a card. Then destroy all creatures.

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Mountain

Color Identity:R

Market Price: $0.22

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/227277_200w.jpg

({T}: Add {R}.)

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Disdainful Stroke

Color Identity:U

Market Price: $0.09

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/176441_200w.jpg

Counter target spell with converted mana cost 4 or greater.

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Castle Ardenvale

Color Identity:W

Market Price: $2.15

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/199390_200w.jpg

Castle Ardenvale enters the battlefield tapped unless you control a Plains.
{T}: Add {W}.
{2}{W}{W}, {T}: Create a 1/1 white Human creature token.

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Fabled Passage

Market Price: $5.59

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/215556_200w.jpg

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle your library. Then if you control four or more lands, untap that land.

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Omen of the Sea

Color Identity:U

Market Price: $0.11

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/206769_200w.jpg

Flash
When Omen of the Sea enters the battlefield, scry 2, then draw a card.
{2}{U}, Sacrifice Omen of the Sea: Scry 2.

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Steam Vents

Color Identity:R,U

Market Price: $7.54

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/175202_200w.jpg

({T}: Add {U} or {R}.)
As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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Deafening Clarion

Color Identity:R,W

Market Price: $0.10

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/176417_200w.jpg

Choose one or both —
• Deafening Clarion deals 3 damage to each creature.
• Creatures you control gain lifelink until end of turn.

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Mystical Dispute

Color Identity:U

Market Price: $0.82

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/198683_200w.jpg

This spell costs {2} less to cast if it targets a blue spell.
Counter target spell unless its controller pays {3}.

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Here is how the best deck in Standard works right now:

From there, Agent of Treachery can be blinked with Yorion, Sky Nomad or bounced with Teferi, Time Raveler to rebuy its enters-the-battlefield trigger. If all of this sounds very mana-intensive to you, you'd be right, but Fires of Invention mitigates that by allowing the deck to circumvent paying mana for stuff; the hypothetical line of play of "cast Agent of Treachery, bounce it with Teferi, Time Raveler, cast Agent of Treachery again" goes from a 14-mana play to a zero-mana one thanks to Fires of Invention.

It's highly relevant that Lukka, Coppercoat Outcast costs five mana. If Polymorph were legal, Standard could have its own straight-up Splinter Twin back again:

You don't even need Fires of Invention to make that work, but it's important to note that Fires of Invention and Polymorph have the same converted mana cost and can be cast on the same turn in succession.

So yeah! It would be nuts to put Polymorph back in Standard.

Never fear. They are not reprinting Polymorph.

Ah, right.

* * *

Some behind-the-scenes insight at how these preview card thingies typically go: Blake Rasmussen hits my inbox with a Magic card that I've never seen before. Then I set up a dartboard with pictures of all of TCGplayer's Magic columnists taped to it, put on a blindfold, and huck a dart. If the dart lands on you, congratulations! You have just been selected to write 1,400 words about Lupine Prototype.

In six years at TCGplayer I've only ever dibsed one card (it was Josu Vess, Lich Knight, for reasons that are still unclear to me), but Transmogrify flew into my inbox at a time when I just so happen to be more curious about the impact on gameplay of "free" Polymorph effects like Lukka, Coppercoat Outcast than ever before in my life. I don't know how it happened but somehow, at one point in time, the best deck in Standard was 80 cards, Polymorphed for a 2/3 that Confiscates, and somehow doesn't sacrifice any power to do so. It could be worth mentioning that it required a couple bans to get there, but the real answer, as Nick Prince touched on last month, is that it's complicated.

Of course, the one time I call dibs on a card something else gets banned in Standard and the whole thing blows up. C'est la vie (French translation: it's the vie). Sometimes you have to beg Blake for an extension on the preview card embargo. Sometimes it works out.

If you're ever curious about a card's casual appeal—about whether or not it's the type of card that could ever catch fire and arbitrarily quadruple in price on an idle Tuesday—its YouTube search results are a fine litmus test.

Magic—and by extension, cards like Polymorph—sculpt epiphanies. The realization that you can stick just one creature in your deck and feed things like Faerie Conclave or Mishra's Factory to a Polymorph to get it for four mana? That realization hits hard. Also worth noting is that the top three thumbnails also feature Emrakul, the Aeons Torn (the most common phone call for LGS employees: "do you uhhh have any Eldrazi"), because 15/15, flying, trample, protection from instants, and Annihilator 6 are pretty darn cool, especially for four mana.

Cards like Polymorph are difficult to design. One of the many sliding scales available to measure cards on is how clever they make you feel. I have provided a visual reference:

Cards like this are touchy. Make it too overt and you've got Fires of Invention. Hide it beneath too many layers of nonsense and you're likely to come up with the next Chains of Mephistopheles (to date, my only experience with Chains of Mephistopheles is from GP New Jersey 2014, where my opponent cast an Italian copy and with it on the stack called a judge to ask for its Oracle text). Make the text box too obvious and before you know it you've built the next link in a long, long, long chain of fan service Doubling Season clones. There are fine lines everywhere.

M21 looks pretty cool so far. I don't usually get excited during preview seasons, but M21 has a lot of cool reprints going for it, along with some other funny things of note. Sparkhunter Masticore, as naked a Teferi, Time Raveler hoser as there ever could be, promises to be the Great Sable Stag of 2020 that couldn't do a single thing to stop the reign of Faeries, a deck roughly 20 times as old as this website. Teferi, Master of Time reintroduces phasing, of all things, an overly unintuitive mechanic that Mark Rosewater admitted is in retrial because the way design has attempted to make creatures as good as spells was to make them spells too (which by the way is the reason that a card as flat-out bonkers as Elder Gargaroth has a great shot at being just plain terrible). Red Polymorph will fit in amongst this motley crew nicely as a card that actually plays better than it reads, not worse.