Maybe

Utvara Hellkite

Flying
Whenever a Dragon you control attacks, create a 6/6 red Dragon creature token with flying.

The Key to the Vault

Whenever equipped creature deals combat damage to a player, look at that many cards from the top of your library. You may exile a nonland card from among them. Put the rest on the bottom of your library in a random order. You may cast the exiled card without paying its mana cost.
Equip {2}{U}

Burning Sands

Whenever a creature dies, that creature's controller sacrifices a land of their choice.

The Tenth Doctor

Allons-y! — Whenever you attack, exile cards from the top of your library until you exile a nonland card. Put three time counters on it. If it doesn't have suspend, it gains suspend.
Timey-Wimey — {7}: Time travel three times. Activate only as a sorcery. (For each suspended card you own and each permanent you control with a time counter on it, you may add or remove a time counter. Then do it two more times.)

Anticipate

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.

Rise of the Eldrazi

This spell can't be countered.
Destroy target permanent. Target player draws four cards. Take an extra turn after this one.
Exile Rise of the Eldrazi.

Cybermen Squadron

Nonlegendary artifact creatures you control have myriad. (Whenever a creature with myriad attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Blightsteel Colossus

Trample, infect, indestructible
If Blightsteel Colossus would be put into a graveyard from anywhere, reveal Blightsteel Colossus and shuffle it into its owner's library instead.

Stasis

Players skip their untap steps.
At the beginning of your upkeep, sacrifice this enchantment unless you pay {U}.

Wildfire

Each player sacrifices four lands of their choice. Wildfire deals 4 damage to each creature.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

The Millennium Calendar

Whenever you untap one or more permanents during your untap step, put that many time counters on The Millennium Calendar.
{2}, {T}: Double the number of time counters on The Millennium Calendar.
When there are 1,000 or more time counters on The Millennium Calendar, sacrifice it and each opponent loses 1,000 life.

Bane of Bala Ged

Whenever this creature attacks, defending player exiles two permanents they control.

Artisan of Kozilek

When you cast this spell, you may return target creature card from your graveyard to the battlefield.
Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Winter Orb

As long as this artifact is untapped, players can't untap more than one land during their untap steps.

Benthic Anomaly

Devoid (This card has no color.)
When you cast this spell, for each opponent, choose a creature that player controls. Create a token that's a copy of one of those creatures, except its power is equal to the total power of those creatures, its toughness is equal to the total toughness of those creatures, and it's a colorless Eldrazi creature.

Mana Breach

Whenever a player casts a spell, that player returns a land they control to its owner's hand.

Star of Extinction

Destroy target land. Star of Extinction deals 20 damage to each creature and each planeswalker.

Time Stretch

Target player takes two extra turns after this one.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Darksteel Colossus

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Indestructible (Damage and effects that say "destroy" don't destroy this creature.)
If Darksteel Colossus would be put into a graveyard from anywhere, reveal Darksteel Colossus and shuffle it into its owner's library instead.

Fury of the Horde

You may exile two red cards from your hand rather than pay this spell's mana cost.
Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase.

Cityscape Leveler

Trample
When you cast this spell and whenever this creature attacks, destroy up to one target nonland permanent. Its controller creates a tapped Powerstone token.
Unearth {8}

Hunted by The Family

Choose up to four target creatures you don't control. For each of them, that creature's controller faces a villainous choice — That creature becomes a 1/1 white Human creature and loses all abilities, or you create a token that's a copy of it.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Portal to Phyrexia

When this artifact enters, each opponent sacrifices three creatures of their choice.
At the beginning of your upkeep, put target creature card from a graveyard onto the battlefield under your control. It's a Phyrexian in addition to its other types.

Terisian Mindbreaker

Whenever this creature attacks, defending player mills half their library, rounded up.
Unearth {1}{U}{U}{U} ({1}{U}{U}{U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Avatar of Slaughter

All creatures have double strike and attack each combat if able.

Desolation Twin

When you cast this spell, create a 10/10 colorless Eldrazi creature token.

Cast Through Time

Instant and sorcery spells you control have rebound. (Exile the spell as it resolves if you cast it from your hand. At the beginning of your next upkeep, you may cast that card from exile without paying its mana cost.)

Bust

Boom

Destroy target land you control and target land you don't control.

Boom // Bust

Deliberate

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Curse of Unbinding

Enchant player
At the beginning of enchanted player's upkeep, that player reveals cards from the top of their library until they reveal a creature card. Put that card onto the battlefield under your control. That player puts the rest of the revealed cards into their graveyard.

Destructive Force

Each player sacrifices five lands of their choice. Destructive Force deals 5 damage to each creature.

Apocalypse

Exile all permanents. You discard your hand.

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Su-Chi Cave Guard

Vigilance
Ward {4} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
When this creature dies, add eight {C}. Until end of turn, you don't lose this mana as steps and phases end.

Flayer of Loyalties

When you cast this spell, gain control of target creature until end of turn. Untap that creature. Until end of turn, it has base power and toughness 10/10 and gains trample, annihilator 2, and haste.
Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)
Trample

Butcher Orgg

You may assign this creature's combat damage divided as you choose among defending player and/or any number of creatures they control.

Cavern-Hoard Dragon

This spell costs {X} less to cast, where X is the greatest number of artifacts an opponent controls.
Flying, trample, haste
Whenever this creature deals combat damage to a player, you create a Treasure token for each artifact that player controls.

Shivan Sand-Mage

When this creature enters, choose one —
• Remove two time counters from target permanent or suspended card.
• Put two time counters on target permanent with a time counter on it or suspended card.
Suspend 4—{R}

Magmatic Force

At the beginning of each upkeep, this creature deals 3 damage to any target.

Breaker of Armies

All creatures able to block this creature do so.

Cursed Recording

Whenever you cast an instant or sorcery spell, put a time counter on this artifact. Then if there are seven or more time counters on it, remove those counters and it deals 20 damage to you.
{T}: When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Walking Skyscraper

This spell costs {1} less to cast for each modified creature you control. (Equipment, Auras you control, and counters are modifications.)
Trample
This creature has hexproof as long as it's untapped. (It can't be the target of spells or abilities your opponents control.)

Fire Tempest

Fire Tempest deals 6 damage to each creature and each player.

Stock Up

Look at the top five cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Mark of Eviction

Enchant creature
At the beginning of your upkeep, return enchanted creature and all Auras attached to that creature to their owners' hands.

Counterspell

Myojin of Roaring Blades

Myojin of Roaring Blades enters with an indestructible counter on it if you cast it from your hand.
Remove an indestructible counter from Myojin of Roaring Blades: It deals 7 damage to each of up to three targets.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Goblin Game

Each player hides at least one item, then all players reveal them simultaneously. Each player loses life equal to the number of items they revealed. The player who revealed the fewest items then loses half their life, rounded up. If two or more players are tied for fewest, each loses half their life, rounded up.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Myojin of Infinite Rage

Myojin of Infinite Rage enters with a divinity counter on it if you cast it from your hand.
Myojin of Infinite Rage has indestructible as long as it has a divinity counter on it.
Remove a divinity counter from Myojin of Infinite Rage: Destroy all lands.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. This land deals 1 damage to you.

Nexus of Fate

Take an extra turn after this one.
If Nexus of Fate would be put into a graveyard from anywhere, reveal Nexus of Fate and shuffle it into its owner's library instead.

The Magic Mirror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
You have no maximum hand size.
At the beginning of your upkeep, put a knowledge counter on The Magic Mirror, then draw a card for each knowledge counter on The Magic Mirror.

Dismiss into Dream

Each creature your opponents control is an Illusion in addition to its other types and has "When this creature becomes the target of a spell or ability, sacrifice it."

Eris, Roar of the Storm

This spell costs {2} less to cast for each different mana value among instant and sorcery cards in your graveyard.
Flying, prowess
Whenever you cast your second spell each turn, create a 4/4 red Dragon Elemental creature token with flying and prowess.

Price of Glory

Whenever a player taps a land for mana, if it's not that player's turn, destroy that land.

Soulfire Eruption

Choose any number of target creatures, planeswalkers, and/or players. For each of them, exile the top card of your library, then Soulfire Eruption deals damage equal to that card's mana value to that permanent or player. You may play the exiled cards until the end of your next turn.

Sorcerous Squall

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Target opponent mills nine cards, then you may cast an instant or sorcery spell from that player's graveyard without paying its mana cost. If that spell would be put into a graveyard, exile it instead.

Eye of the Storm

Whenever a player casts an instant or sorcery card, exile it. Then that player copies each instant or sorcery card exiled with this enchantment. For each copy, the player may cast the copy without paying its mana cost.

Jhoira's Timebug

{T}: Choose target permanent you control or suspended card you own. If that permanent or card has a time counter on it, you may remove a time counter from it or put another time counter on it.

Winter Moon

Players can't untap more than one nonbasic land during their untap steps.

Izzet Cluestone

{T}: Add {U} or {R}.
{U}{R}, {T}, Sacrifice this artifact: Draw a card.

Mountain

Thieves' Auction

Exile all nontoken permanents. Starting with you, each player chooses one of the exiled cards and puts it onto the battlefield tapped under their control. Repeat this process until all cards exiled this way have been chosen.

Clockspinning

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Choose a counter on target permanent or suspended card. Remove that counter from that permanent or card or put another of those counters on it.

Void Winnower

Your opponents can't cast spells with even mana values. (Zero is even.)
Your opponents can't block with creatures with even mana values.

Otherworldly Gaze

Surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Bearer of the Heavens

When this creature dies, destroy all permanents at the beginning of the next end step.

Chaos Maw

When this creature enters, it deals 3 damage to each other creature.

Epicenter

Target player sacrifices a land of their choice.
Threshold — Each player sacrifices all lands they control instead if seven or more cards are in your graveyard.

Tidal Force

At the beginning of each upkeep, you may tap or untap target permanent.

Keldon Firebombers

When this creature enters, each player sacrifices all lands they control except for three.

Ruination

Mind's Dilation

Whenever an opponent casts their first spell each turn, that player exiles the top card of their library. If it's a nonland card, you may cast it without paying its mana cost.

Aminatou's Augury

Exile the top eight cards of your library. You may put a land card from among them onto the battlefield. Until end of turn, for each nonland card type, you may cast a spell of that type from among the exiled cards without paying its mana cost.

Eternal Dominion

Search target opponent's library for an artifact, creature, enchantment, or land card. Put that card onto the battlefield under your control. Then that player shuffles.
Epic (For the rest of the game, you can't cast spells. At the beginning of each of your upkeeps, copy this spell except for its epic ability. You may choose a new target for the copy.)

Sol Ring

Strip Mine

{T}: Add {C}.
{T}, Sacrifice this land: Destroy target land.

Sulfur Falls

This land enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Devastation

Expropriate

Council's dilemma — Starting with you, each player votes for time or money. For each time vote, take an extra turn after this one. For each money vote, choose a permanent owned by the voter and gain control of it. Exile Expropriate.

Killer

Killer deals 3 damage to target creature and each other creature that shares a creature type with it.

Coward

Target creature can't block this turn and becomes a Coward in addition to its other types until end of turn.
Time travel.

Coward // Killer

Collision of Realms

Each player shuffles all creatures they own into their library. Each player who shuffled a nontoken creature into their library this way reveals cards from the top of their library until they reveal a creature card, then puts that card onto the battlefield and the rest on the bottom of their library in a random order.

Obsessive Search

Draw a card.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

The Moment

At the beginning of your upkeep, put a time counter on The Moment.
{2}, {T}: Untap target creature you control. It phases out until The Moment leaves the battlefield.
{3}, {T}: Destroy each nonland permanent with mana value less than or equal to the number of time counters on The Moment. Then sacrifice The Moment. Activate only as a sorcery.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Jin-Gitaxias, Core Augur

Flash
At the beginning of your end step, draw seven cards.
Each opponent's maximum hand size is reduced by seven.

Ulamog, the Ceaseless Hunger

When you cast this spell, exile two target permanents.
Indestructible
Whenever Ulamog attacks, defending player exiles the top twenty cards of their library.

Astral Dragon

Flying
Project Image — When this creature enters, create two tokens that are copies of target noncreature permanent, except they're 3/3 Dragon creatures in addition to their other types, and they have flying.

Knowledge Exploitation

Prowl {3}{U} (You may cast this for its prowl cost if you dealt combat damage to a player this turn with a Rogue.)
Search target opponent's library for an instant or sorcery card. You may cast that card without paying its mana cost. Then that player shuffles.

Platinum Emperion

Your life total can't change. (You can't gain or lose life. You can't pay any amount of life except 0.)

Beacon of Tomorrows

Target player takes an extra turn after this one. Shuffle Beacon of Tomorrows into its owner's library.

Kozilek, the Great Distortion

When you cast this spell, if you have fewer than seven cards in hand, draw cards equal to the difference.
Menace
Discard a card with mana value X: Counter target spell with mana value X.