In researching Mordenkainen, I discovered that he's easily one of the most powerful and well-known characters in D&D lore. (Hey, ya learn something new every day.) But what to pair with this iconic wizard? Well, to me, there's nothing that epitomizes D&D more than rolling dice. 

...Granted, my knowledge base on the subject matter is a little bit lacking. But WoTC put dice rolling into the set, and they made it Blue, so I'm going to take that and run with it. (Roll with it?) Of course, I'll aim to throw in some of the Dragons as well.

Here's what Mordenkainen is bringing to the table: 

Magic: The Gathering TCG Deck - Mordenkainen by Andy Hurst

'Mordenkainen' - constructed deck list and prices for the Magic: The Gathering Trading Card Game from TCGplayer Infinite!

Created By: Andy Hurst

Event:

Rank: 0-0

Freeform (Casual)

Market Price: $9.02

Cards

Said // Done

Color Identity:U

Market Price: $0.01

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/240230_200w.jpg

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You Come to a River

Color Identity:U

Market Price: $0.03

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243066_200w.jpg

Choose one —
• Fight the Current — Return target nonland permanent to its owner's hand.
• Find a Crossing — Target creature gets +1/+0 until end of turn and can't be blocked this turn.

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Mordenkainen's Polymorph

Color Identity:U

Market Price: $0.01

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243111_200w.jpg

Until end of turn, target creature becomes a Dragon with base power and toughness 4/4 and gains flying. (It loses all other creature types.)

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Treasure Chest

Market Price: $0.37

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{4}, Sacrifice Treasure Chest: Roll a d20.
1 | Trapped! — You lose 3 life.
2—9 | Create five Treasure tokens.
10—19 | You gain 3 life and draw three cards.
20 | Search your library for a card. If it's an artifact card, you may put it onto the battlefield. Otherwise, put that card into your hand. Then shuffle.

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Feywild Trickster

Color Identity:U

Market Price: $0.07

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243259_200w.jpg

Whenever you roll one or more dice, create a 1/1 blue Faerie Dragon creature token with flying.

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Mind Flayer

Color Identity:U

Market Price: $0.43

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243361_200w.jpg

Dominate Monster — When Mind Flayer enters the battlefield, gain control of target creature for as long as you control Mind Flayer.

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Coralhelm Guide

Color Identity:U

Market Price: $0.02

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/167865_200w.jpg

{4}{U}: Target creature can't be blocked this turn.

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Floodhound

Color Identity:U

Market Price: $0.01

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/240206_200w.jpg

{3}, {T}: Investigate. (Create a colorless Clue artifact token with "{2}, Sacrifice this artifact: Draw a card.")

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Djinni Windseer

Color Identity:U

Market Price: $0.01

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243257_200w.jpg

Flying
When Djinni Windseer enters the battlefield, roll a d20.
1—9 | Scry 1.
10—19 | Scry 2.
20 | Scry 3.

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Memorial to Genius

Color Identity:U

Market Price: $0.05

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Memorial to Genius enters the battlefield tapped.
{T}: Add {U}.
{4}{U}, {T}, Sacrifice Memorial to Genius: Draw two cards.

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Skyline Cascade

Color Identity:U

Market Price: $0.08

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/105378_200w.jpg

Skyline Cascade enters the battlefield tapped.
When Skyline Cascade enters the battlefield, target creature an opponent controls doesn't untap during its controller's next untap step.
{T}: Add {U}.

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Trickster's Talisman

Color Identity:U

Market Price: $0.05

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Invoke Duplicity — Equipped creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may sacrifice Trickster's Talisman. If you do, create a token that's a copy of this creature."
Equip {2}

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Courtly Provocateur

Color Identity:U

Market Price: $0.11

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/59931_200w.jpg

{T}: Target creature attacks this turn if able.
{T}: Target creature blocks this turn if able.

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Prodigal Sorcerer

Color Identity:U

Market Price: $0.13

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/118449_200w.jpg

{T}: Prodigal Sorcerer deals 1 damage to any target.

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Wizard's Spellbook

Color Identity:U

Market Price: $0.27

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{T}: Exile target instant or sorcery card from a graveyard. Roll a d20. Activate only as a sorcery.
1—9 | Copy that card. You may cast the copy.
10—19 | Copy that card. You may cast the copy by paying {1} rather than paying its mana cost.
20 | Copy each card exiled with Wizard's Spellbook. You may cast any number of the copies without paying their mana costs.

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Arcane Investigator

Color Identity:U

Market Price: $0.01

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243275_200w.jpg

Search the Room — {5}{U}: Roll a d20.
1—9 | Draw a card.
10—20 | Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

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Moonring Island

Color Identity:U

Market Price: $0.28

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/18714_200w.jpg

({T}: Add {U}.)
Moonring Island enters the battlefield tapped.
{U}, {T}: Look at the top card of target player's library. Activate only if you control two or more blue permanents.

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Icefall Regent

Color Identity:U

Market Price: $0.45

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/132253_200w.jpg

Flying
When Icefall Regent enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's untap step for as long as you control Icefall Regent.
Spells your opponents cast that target Icefall Regent cost {2} more to cast.

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Charmed Sleep

Color Identity:U

Market Price: $0.01

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243037_200w.jpg

Enchant creature
When Charmed Sleep enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

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Pixie Guide

Color Identity:U

Market Price: $0.04

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243252_200w.jpg

Flying
Grant an Advantage — If you would roll one or more dice, instead roll that many dice plus one and ignore the lowest roll.

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Mordenkainen

Color Identity:U

Market Price: $3.27

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243410_200w.jpg

+2: Draw two cards, then put a card from your hand on the bottom of your library.
−2: Create a blue Dog Illusion creature token with "This creature's power and toughness are each equal to twice the number of cards in your hand."
−10: Exchange your hand and library, then shuffle. You get an emblem with "You have no maximum hand size."

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Phantasmal Dreadmaw

Color Identity:U

Market Price: $0.01

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/239798_200w.jpg

Trample
When Phantasmal Dreadmaw becomes the target of a spell or ability, sacrifice it.

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You Find the Villains' Lair

Color Identity:U

Market Price: $0.13

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243104_200w.jpg

Choose one —
• Foil Their Scheme — Counter target spell.
• Learn Their Secrets — Draw two cards, then discard two cards.

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Scion of Stygia

Color Identity:U

Market Price: $0.01

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243263_200w.jpg

Flash
Cone of Cold — When Scion of Stygia enters the battlefield, choose target creature an opponent controls, then roll a d20.
1—9 | Tap that creature.
10—20 | Tap that creature. It doesn't untap during its controller's next untap step.

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Power of Persuasion

Color Identity:U

Market Price: $0.02

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243276_200w.jpg

Choose target creature an opponent controls, then roll a d20.
1—9 | Return it to its owner's hand.
10—19 | Its owner puts it on the top or bottom of their library.
20 | Gain control of it until the end of your next turn.

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Silumgar's Scorn

Color Identity:U

Market Price: $0.16

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/96523_200w.jpg

As an additional cost to cast this spell, you may reveal a Dragon card from your hand.
Counter target spell unless its controller pays {1}. If you revealed a Dragon card or controlled a Dragon as you cast this spell, counter that spell instead.

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Repel

Color Identity:U

Market Price: $0.09

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/9373_200w.jpg

Put target creature on top of its owner's library.

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You See a Guard Approach

Color Identity:U

Market Price: $0.03

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243048_200w.jpg

Choose one —
• Distract the Guard — Tap target creature.
• Hide — Target creature you control gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

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Contact Other Plane

Color Identity:U

Market Price: $0.05

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243245_200w.jpg

Roll a d20.
1—9 | Draw two cards.
10—19 | Scry 2, then draw two cards.
20 | Scry 3, then draw three cards.

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Wizard Class

Color Identity:U

Market Price: $1.00

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(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

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Aberrant Mind Sorcerer

Color Identity:U

Market Price: $0.06

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243580_200w.jpg

Psionic Spells — When Aberrant Mind Sorcerer enters the battlefield, choose target instant or sorcery card in your graveyard, then roll a d20.
1—9 | You may put that card on top of your library.
10—20 | Return that card to your hand.

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Blue Dragon

Color Identity:U

Market Price: $0.08

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243360_200w.jpg

Flying
Lightning Breath — When Blue Dragon enters the battlefield, until your next turn, target creature an opponent controls gets -3/-0, up to one other target creature gets -2/-0, and up to one other target creature gets -1/-0.

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Spiked Pit Trap

Market Price: $0.01

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/243212_200w.jpg

Flash
{5}, {T}, Sacrifice Spiked Pit Trap: Choose target creature, then roll a d20.
1—9 | Spiked Pit Trap deals 5 damage to that creature.
10—20 | Spiked Pit Trap deals 5 damage to that creature. Create a Treasure token.

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Island

Color Identity:U

Market Price: $0.06

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/196609_200w.jpg

({T}: Add {U}.)

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Desert of the Mindful

Color Identity:U

Market Price: $0.07

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/236225_200w.jpg

Desert of the Mindful enters the battlefield tapped.
{T}: Add {U}.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)

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Hard Evidence

Color Identity:U

Market Price: $0.06

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/240208_200w.jpg

Create a 0/3 blue Crab creature token.
Investigate. (Create a colorless Clue artifact token with "{2}, Sacrifice this artifact: Draw a card.")

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Phantasmal Dragon

Color Identity:U

Market Price: $0.16

ImageURL: https://tcgplayer-cdn.tcgplayer.com/product/79985_200w.jpg

Flying
When Phantasmal Dragon becomes the target of a spell or ability, sacrifice it.

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The Game Plan

We're here to roll some dice, play some dragons, and attack with gigantic Good Boys. We're using as many die rollers as we can - 11 in total - and we also have the right enablers and payoffs with Pixie Guides for the advantages and Feywild Tricksters for the flying tokens. Obviously, we'd love to get these online before we start rolling. 

As far as the general path to victory, we're not terribly unique for a Blue deck. We want to win the game by attacking with flyers, ranging from little faerie dragon tokens to Icefall Regent and Blue Dragon. Keep in mind that because of those little faerie dragons, our Silumgar's Scorn will be an actual Counterspell a huge chunk of the time. 

Because Mordenkainen makes illusory dogs, I made sure to add some other make-believe backup. Phantasmals Dreadmaw and Dragon add massive (but fragile) punch, so get in hits with them when you can, but try not to depend too much on them. As an added flavor touch, Floodhound is here and actually works quite well with our Planeswalker. It's another blue doggie for the flavor win, and it churns out clues, which will make Mordenkainen's hounds much larger. On that note, You Find the Villains' Lair and You See a Guard Approach just screamed out flavor wins and I couldn't leave them unplayed. 

Our removal package is lacking, which shouldn't surprise as a Mono Blue deck. But it's not all bad. Spiked Pit Trap should kill anything but the Greenest Rares, Charmed Sleep can keep a dangerous threat locked down, and we have a few counterspells to keep the big bad threats away. We also have the opportunity to roll several dice that can result in those tokens, which allows us to trade them off either individually or in batches — a luxury Blue is not often afforded. 

The Rares

Blue "removal" plus a large(ish) flyer plus it's a Dragon! This seems like a pretty ideal fit here, and this is a creature we're interested in seeing every single game. Sure, we don't get to roll any dice with this beasty, but this does hold down the fort and kill the opponent while we get to roll all the dice we want. Seems like a pretty fair compromise. 

My D&D knowledge doesn't go quite deep enough to get the full flavor implications of the Mind Flayer, but I was playing Magic years ago when Sower of Temptation was around Standard and man, that thing was a savage, savage beating. It was a force in Standard, it was played in Extended (think Modern for you Zoomers), and even got played in Legacy at the time. The ability to wield a Control Magic that also attacks and blocks on its own is very potent. So we're going to play this new D&D-themed Sower and cackle with glee as the opponent's best creature (hopefully a Rare one) shows where its loyalty truly lies. 

Ah, a Dice-Rolling Rare — just what we're looking for. This is going to be a pretty solid one for us...as long as we don't roll that 1. That will be devastating, so if given the chance, remember to deploy a Pixie Guide first. We'd be just fine with any of the other three outcomes most of the time, with 11-19 the most preferable. Drawing 3 cards is a nice one, and this deck doesn't have a plethora of ways to gain life otherwise. Should we roll that 20, we've got a pair of pretty solid options: we can get the Spiked Pit Trap for removal, or we can get that last Rare…

Oh my goodness! I didn't see you there! How convenient. If we've got the time for it, this will make for a potent late-game finisher. We'll need to keep a few different things in mind here: first, I know it says so right on the card, but just remember we can only activate it as a sorcery. When I read it, I see that it can get instants OR sorceries, and my mind immediately goes to instant-speed shenanigans. So those are out. Next, keep in mind that we absolutely can cast our opponent's spells! We aren't confined to just our graveyard. However, unlike a lot of the similar effects printed recently that enable casting our opponent's spells, we can't automatically cast them if they require non-Blue mana. So IF we roll 10-20, we're in luck, or if we got the Treasure from the Treasure Chest earlier this might be a wise future expenditure of that gold. Lastly, rolling a 20 on this is gonna feel really amazing...so let's hope for that. 

Unsung Hero

This little trinket delivers the goods. First, it's cheap to cast and cheap to equip — always a positive for any equipment. Next, it grants a size bonus. Sure, it's only +1/+1, but that's usually enough to turn the average Blue creature into a contender on the board. In our deck, it makes Pixie Guide into a phenomenal blocker, turns Djinni Windseer into a great attacker, and I can't even fathom the size of a 6/6 Blue Dragon. Lastly, the ability when it connects can be massive. We'll generally be most interested in something that connects easily like Djinni Windseer; we'll get another die roll out of it along with a solid evasive threat. If we can ever swing it, Prodigal Sorcerer would be a great target, simce duplicates of that thing will allow us to control a board pretty well. And obviously with either of our Rare creatures, the Talisman will help make a game unlosable. Just remember that it really doesn't work with our Phantasmal creatures!