Myntasha, Honored One

As an additional cost to cast this spell, you may open a sealed Magic booster pack and put the cards on the bottom of your booster pile in a random order.
Spells you cast have booster cascade. (It's like cascade, but use your booster pile rather than your library.)

Andrios, Roaming Explorer

Reach
As long as Andrios is attacking, tapped creatures you control with base power and toughness 4/3 have base power and toughness 16/9.
{T}: Add {W}{U}{B}{R}{G}. Creature spells you spend this mana to cast have their base power and toughness become 4/3.

Yule Ooze

At the beginning of your upkeep, destroy another nonland permanent chosen at random, then put a number of +1/+1 counters on Yule Ooze equal to that permanent's converted mana cost.
{R}{G}, Eat some food: Regenerate Yule Ooze.

Last-Minute Chopping

Ask target opponent if they remembered to get you a present. If they say yes, they put a card they own from outside the game into your hand. Otherwise, you gain control of target permanent they control.

Shichifukujin Dragon

When Shichifukujin Dragon comes into play, put seven +1/+1 counters on it.
{R}{R}{R}, Sacrifice two +1/+1 counters: Put three +1/+1 counters on Shichifukujin Dragon at end of turn. Play this ability as a sorcery.

Euroakus

When Euroakus enters, create a number of 1/1 blue Human Wizard creature tokens equal to the number of differently named lands you control.
{4}{G}{U}: Draw a card for each Wizard you control. They each get +1/+1 until end of turn for each card in your hand.

Elusen, the Giving

Flying, vigilance, lifelink, haste
At the beginning of your second main phase, the player to your left gains control of Elusen, the Giving.
Whenever a player donates a permanent to another player, the donating player draws a card, gains 1 life, and creates three Treasure tokens.

War of the Spark

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Each player may put a planeswalker or Zombie card from War of the Spark from their hand or graveyard onto the battlefield.
II — Sacrifice any number of creatures and/or planeswalkers. Each opponent sacrifices that many creatures and/or planeswalkers.
III — Exile up to one target Bolas. Proliferate three times.

Fruitcake Elemental

Fruitcake Elemental is indestructible.
At the end of your turn, Fruitcake Elemental deals 7 damage to you.
{3}: Target player gains control of Fruitcake Elemental.

Chaos Wrap

The owner of target permanent shuffles it into their library. Then they may look at the top card of their library and may wrap it. If it's a permanent card, they may put it onto the battlefield. Otherwise, they may put it onto the battlefield face down as a 4/4 red Present creature. (To wrap a card, put it inside lots of sleeves. If it would be dealt damage or destroyed, remove a sleeve from it instead.)

M'Odo, the Gnarled Oracle

Eminence — {X}, Discard a card: Target player reveals cards from the top of their library until they reveal a creature card with converted mana cost X or less. Put that card onto the battlefield under your control, then that player shuffles the rest into their library. Activate this ability only if M'Odo, the Gnarled Oracle is on the battlefield or in the command zone.

Mountain Mover

Flying, haste
Whenever Mountain Mover enters or attacks, put a Mountain card from outside the game underneath it.
When Mountain Mover leaves the battlefield, put all cards underneath it onto the battlefield.
Crew 3

Evil Presents

Put a creature card from your hand into play under target opponent's control. That creature attacks each turn if able . . . and always attacks its controller.

Nice

Search your library for a card and put it into another target player's hand. Then shuffle your library.

Naughty

Search another target player's library for a card and put that card into your hand. Then shuffle that player's library.

Naughty // Nice

Gifts Given

Search target opponent's library for four cards with different names and reveal them. That player chooses two of those cards. Put the chosen cards into the player's graveyard and the rest into your hand. Then that player shuffles their library.

Mishra's Toy Workshop

{T}: Add {C}{C}{C}. Spend this mana only on spells and abilities that put tokens onto the battlefield. Use toys to represent the tokens.

Some Disassembly Required

{B}, Sacrifice a creature: Distribute the sacrificed creature's keyword abilities among any number of other target creatures until end of turn. If it's December, you gain 1 life for each of those keywords.

Inzerva, Master of Insights

+2: Draw two cards, then discard a card.
−2: Look at the top two cards of each other player's library, then put any number of them on the bottom of that library and the rest on top in any order. Scry 2.
−4: You get an emblem with "Your opponents play with their hands revealed" and "Whenever an opponent draws a card, this emblem deals 1 damage to them."

Arteeoh, Dread Scavenger

Flying, deathtouch
Whenever Arteeoh deals combat damage to a player, you may exchange control of two other target artifacts. When you do, create a token that's a copy of target artifact you don't control, except it's a 1/1 green Squirrel creature token in addition to its other colors and types.

Eggnogger's 'Stache

Lands you control have "{T}: Refill your mug with a festive drink." (If you don't have a mug, go grab a mug! It's the holidays!)
At the beginning of combat on your turn, if you have a drink 'stache, put two +1/+1 counters on each creature you control.

Discord, Lord of Disharmony

Flying
At the beginning of your end step, choose a random nonland Magic card name. Until your next end step, you may cast a copy of a spell with that name, and mana of any type can be spent to cast it. If you cast a spell this way, copy this ability if Discord is on the battlefield.

The Cinematic Phoenix

Flying, haste, protection from red
{1}, {T}: Return target legendary creature card from your graveyard to the battlefield.
Tap six untapped creatures you control: Return The Cinematic Phoenix from your graveyard to the battlefield. If you tapped six legendary creatures this way, you win the game.

Join the Group

You may put a legendary creature card from your hand into the command zone. It's also your commander.

Champions of Archery

Reach
Commanders you control get +X/+0, where X is the number of commanders you control.

Champions of Archery // Join the Group

Fabled Path of Searo Point

{W}{U}{B}{R}{G}, {T}: Creatures you control gain landwalk until end of turn.

Only the Best

Return target Booster Fun card from your graveyard to your hand.

Collectigull

Flying, protection from common
Whenever Collectigull attacks, reveal the top card of your library. If it's a Booster Fun card, you may put it into your hand.

Collectigull // Only the Best

The Legend of Arena

The Legend of Arena can be your commander.
I, II — Create a 2/1 red Human Wizard creature token. Spells you cast this turn cost {1} less to cast for each Wizard you control.
III — Search your library for a planeswalker card, put it onto the battlefield, then shuffle your library. It enters with an additional loyalty counter on it for each Wizard you control.

Heroes of Kamigawa

Each spell you cast with a name printed in a Kamigawa expansion costs {1} less to cast.
+2: Open up to one sealed Kamigawa booster pack and shuffle those cards into your booster pile. Look at the top four cards of your booster pile. Put two of those cards into your hand and the rest into your graveyard.
−3: Return a creature card with a name printed in a Kamigawa expansion from your graveyard to the battlefield.
Heroes of Kamigawa can be your commander.

1996 World Champion

Cannot be the target of spells or effects. World Champion has power and toughness equal to the life total of target opponent.
{0}: Discard your hand to search your library for 1996 World Champion and reveal it to all players. Shuffle your library and put 1996 World Champion on top of it. Use this ability only at the beginning of your upkeep, and only if 1996 World Champion is in your library.

Ersta, Friend to All

+1: Create a 1/1 Human Wizard creature token that's all colors.
−3: Choose a card name from among Enlightened Tutor, Mystical Tutor, Booster Tutor, Imperial Recruiter, and Worldly Tutor. Create a copy of the card with the chosen name. You may cast the copy without paying its mana cost.
−8: You get an emblem with "At the beginning of your upkeep, if you control twenty or more Wizards, you win the game."
Ersta, Friend to All can be your commander.

The Secret Lair

{T}: Add {C}.
{T}, Say the secret word: Add one mana of any color. Scry 1. You gain 1 life.

Shahrazad

Players play a Magic subgame, using their libraries as their decks. Each player who doesn't win the subgame loses half their life, rounded up.

Thopter Pie Network

At the beginning of your upkeep, if you're eating, create a 1/1 colorless Thopter artifact creature token with flying. Use food to represent the token.
Whenever a creature token you control dies, if it's represented by food, eat it.

Bog Humbugs

Flying
Whenever Bog Humbugs deals combat damage, hum that many notes of a festive song. If you can, put a +1/+1 counter on Bog Humbugs.

Diabolical Salvation

Split second
Create four 4/4 red Devil creature tokens with haste and "When this creature dies, create a colorless Treasure artifact token with '{T}, Sacrifice this artifact: Add one mana of any color.'" Sacrifice the Devil tokens at the beginning of the next end step.

Seasonal Sequels

Pitch the titles of up to X holiday-themed sequels to target spell. Copy that spell for each title pitched, except the copy has that name. You may choose new targets for the copies. (Simply adding numbers isn't festive enough.)

Topdeck the Halls

Decorated cards in your hand have miracle {S}. (Decorated cards include premiums, promos, and cards with alternate frames or art.)
At the beginning of your upkeep, if you control twelve or more decorated permanents, you win the game.

Kharis & The Beholder

Flying
When Kharis & The Beholder enters and at the beginning of your upkeep, create a 1/1 white Human creature token and make a charisma check. (Roll a d20.)
• If the result plus the number of creatures you control is greater than 11, put a +1/+1 counter on each creature you control.
• If the result is a natural 20, for each nonlegendary creature you control, create a token that's a copy of that creature.

Sol, Advocate Eternal

Legendary partner (You can have two commanders if this is one of them. The other one is promoted to legendary.)
Flying, vigilance
Teamwork — Whenever you attack or block with both Sol, Advocate Eternal and its partner, support 4 and investigate four times.

Svega, the Unconventional

Landfall — Whenever a land enters under your control, put a loyalty counter on target planeswalker.
−2: For each planeswalker type among planeswalkers you control, create a 1/1 Attendee creature token that's all colors.
−X: Choose an Elspeth, Teferi, Liliana, Chandra, or Garruk planeswalker card name with mana value X. Create a copy of the card with the chosen name. You may cast the copy without paying its mana cost.
Svega can be your commander.

Goblin Sleigh Ride

Target creature you control climbs into Goblin Sleigh Ride. You slide them on their merry way. If the creature stayed on, it deals damage equal to its toughness to each other creature touched during the slide.

Present Arms

Exchange your library with another deck you own from outside the game. Shuffle your library.

Decorated Knight

Whenever Decorated Knight attacks, draw a card from your original deck if it's outside the game.

Decorated Knight // Present Arms

Byode, Inverse Sun

+2: Mill three cards, then return any number of cards from different Universes milled this way from your graveyard to your hand.
-X: Choose a Universe you haven't chosen this way this game. You may cast a spell from that Universe with mana value X or less from your hand without paying its mana cost.
Byode, Inverse Sun can be your commander.
Your deck can include Universes Beyond cards of any color identity.

Treizeci, Sun of Serra

Companion — Your starting deck contains only nostalgic cards. (Retro frames, legends, and artifacts are nostalgic.)
Vigilance
Whenever you cast a nostalgic spell, you may pay {2}. If you do, put a +1/+1 counter on Treizeci, then for each +1/+1 counter on it, create a Serra Angel token.

Keeper of the Secret Lair

Flash
You may cast Secret Lair spells as though they had flash.
Secret Lair spells you cast cost {1} less to cast.