Dragon Breath

Enchant creature
Enchanted creature has haste.
{R}: Enchanted creature gets +1/+0 until end of turn.
When a creature with mana value 6 or greater enters, you may return Dragon Breath from your graveyard to the battlefield attached to that creature.

Kurgadon

Whenever you cast a creature spell with mana value 6 or greater, put three +1/+1 counters on Kurgadon.

Morbid Curiosity

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw cards equal to the mana value of the sacrificed permanent.

Accelerated Mutation

Target creature gets +X/+X until end of turn, where X is the highest mana value among permanents you control.

Distended Mindbender

Emerge {5}{B}{B} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, target opponent reveals their hand. You choose from it a nonland card with mana value 3 or less and a card with mana value 4 or greater. That player discards those cards.

Disaster Radius

As an additional cost to cast this spell, reveal a creature card from your hand.
Disaster Radius deals X damage to each creature your opponents control, where X is the revealed card's mana value.

Sorin, Grim Nemesis

+1: Reveal the top card of your library and put that card into your hand. Each opponent loses life equal to its mana value.
−X: Sorin, Grim Nemesis deals X damage to target creature or planeswalker and you gain X life.
−9: Create a number of 1/1 black Vampire Knight creature tokens with lifelink equal to the highest life total among all players.

Burnt Offering

As an additional cost to cast this spell, sacrifice a creature.
Add X mana in any combination of {B} and/or {R}, where X is the sacrificed creature's mana value.

Ancient Stone Idol

Flash
This spell costs {1} less to cast for each attacking creature.
Trample
When Ancient Stone Idol dies, create a 6/12 colorless Construct artifact creature token with trample.

Krosan Drover

Creature spells you cast with mana value 6 or greater cost {2} less to cast.

Elder Deep-Fiend

Flash
Emerge {5}{U}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, tap up to four target permanents.

Baneful Omen

At the beginning of your end step, you may reveal the top card of your library. If you do, each opponent loses life equal to that card's mana value.

Psychic Battle

Whenever a player chooses one or more targets, each player reveals the top card of their library. The player who reveals the card with the highest mana value may change the target or targets. If two or more cards are tied for highest, the target or targets remain unchanged. Changing targets this way doesn't trigger abilities of permanents named Psychic Battle.

Aura Mutation

Destroy target enchantment. Create X 1/1 green Saproling creature tokens, where X is that enchantment's mana value.

Aether Mutation

Return target creature to its owner's hand. Create X 1/1 green Saproling creature tokens, where X is that creature's mana value.

Stormchaser Chimera

Flying
{2}{U}{R}: Scry 1, then reveal the top card of your library. Stormchaser Chimera gets +X/+0 until end of turn, where X is that card's mana value. (To scry 1, look at the top card of your library, then you may put that card on the bottom.)

Combustible Gearhulk

First strike
When Combustible Gearhulk enters, target opponent may have you draw three cards. If the player doesn't, you mill three cards, then Combustible Gearhulk deals damage to that player equal to the total mana value of those cards.

Timesifter

At the beginning of each upkeep, each player exiles the top card of their library. The player who exiled the card with the highest mana value takes an extra turn after this one. If two or more players' cards are tied for highest, the tied players repeat this process until the tie is broken.

Woodland Guidance

Return target card from your graveyard to your hand. Clash with an opponent. If you win, untap all Forests you control. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)
Exile Woodland Guidance.

Dralnu's Pet

Kicker—{2}{B}, Discard a creature card. (You may pay {2}{B} and discard a creature card in addition to any other costs as you cast this spell.)
If Dralnu's Pet was kicked, it enters with flying and with X +1/+1 counters on it, where X is the discarded card's mana value.

Surge of Strength

As an additional cost to cast this spell, discard a red or green card.
Target creature gains trample and gets +X/+0 until end of turn, where X is that creature's mana value.

Bludgeon Brawl

Each noncreature, non-Equipment artifact is an Equipment with equip {X} and "Equipped creature gets +X/+0," where X is that artifact's mana value.

Demonlord Belzenlok

Flying, trample
When Demonlord Belzenlok enters, exile cards from the top of your library until you exile a nonland card, then put that card into your hand. If the card's mana value is 4 or greater, repeat this process. Demonlord Belzenlok deals 1 damage to you for each card put into your hand this way.

Angel of Salvation

Flash; 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.)
Flying
When Angel of Salvation enters, prevent the next 5 damage that would be dealt this turn to any number of targets, divided as you choose.

Avatar of Fury

If an opponent controls seven or more lands, this spell costs {6} less to cast.
Flying
{R}: Avatar of Fury gets +1/+0 until end of turn.

Forge Armor

As an additional cost to cast this spell, sacrifice an artifact.
Put X +1/+1 counters on target creature, where X is the sacrificed artifact's mana value.

Induce Despair

As an additional cost to cast this spell, reveal a creature card from your hand.
Target creature gets -X/-X until end of turn, where X is the revealed card's mana value.

Hoarder's Greed

You lose 2 life and draw two cards, then clash with an opponent. If you win, repeat this process. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Dragon Wings

Enchant creature
Enchanted creature has flying.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When a creature with mana value 6 or greater enters, you may return Dragon Wings from your graveyard to the battlefield attached to that creature.

Boon of Boseiju

Target creature gets +X/+X until end of turn, where X is the greatest mana value among permanents you control. Untap it.

Avatar of Might

If an opponent controls at least four more creatures than you, this spell costs {6} less to cast.
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Adipose Offspring

Emerge {5}{W} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When Adipose Offspring enters, create a 2/2 white Alien creature token. If Adipose Offspring's emerge cost was paid, instead create X of those tokens, where X is the sacrificed creature's toughness.

Dragon Fangs

Enchant creature
Enchanted creature gets +1/+1 and has trample.
When a creature with mana value 6 or greater enters, you may return Dragon Fangs from your graveyard to the battlefield attached to that creature.

Greater Gargadon

Suspend 10—{R}
Sacrifice an artifact, creature, or land: Remove a time counter from Greater Gargadon. Activate only if Greater Gargadon is suspended.

Sacrifice

As an additional cost to cast this spell, sacrifice a creature.
Add an amount of {B} equal to the sacrificed creature's mana value.

Heed the Mists

Mill a card, then draw cards equal to the milled card's mana value.

Ancient Ooze

Ancient Ooze's power and toughness are each equal to the total mana value of other creatures you control.

Mockery of Nature

Emerge {7}{G} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, you may destroy target artifact or enchantment.

Volcanic Vision

Return target instant or sorcery card from your graveyard to your hand. Volcanic Vision deals damage equal to that card's mana value to each creature your opponents control. Exile Volcanic Vision.

Hedron Matrix

Equipped creature gets +X/+X, where X is its mana value.
Equip {4}

Judge Unworthy

Choose target attacking or blocking creature. Scry 3, then reveal the top card of your library. Judge Unworthy deals damage equal to that card's mana value to that creature.

Maelstrom Djinn

Flying
Morph {2}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Maelstrom Djinn is turned face up, put two time counters on it and it gains vanishing. (At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)

Toymaker

{1}, {T}, Discard a card: Target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value until end of turn. (It retains its abilities.)

Death's Oasis

Whenever a nontoken creature you control dies, mill two cards. Then return a creature card with lesser mana value than the creature that died from your graveyard to your hand.
{1}, Sacrifice Death's Oasis: You gain life equal to the highest mana value among creatures you control.

Soldevi Adnate

{T}, Sacrifice a black or artifact creature: Add an amount of {B} equal to the sacrificed creature's mana value.

Dragon Shadow

Enchant creature
Enchanted creature gets +1/+0 and has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
When a creature with mana value 6 or greater enters, you may return Dragon Shadow from your graveyard to the battlefield attached to that creature.

Favor of the Mighty

Each creature with the highest mana value has protection from each color.

Avatar of Woe

If there are ten or more creature cards total in all graveyards, this spell costs {6} less to cast.
Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
{T}: Destroy target creature. It can't be regenerated.

Liege of the Pit

Flying, trample
At the beginning of your upkeep, sacrifice a creature other than Liege of the Pit. If you can't, Liege of the Pit deals 7 damage to you.
Morph {B}{B}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Infernal Genesis

At the beginning of each player's upkeep, that player mills a card. Then they create X 1/1 black Minion creature tokens, where X is the milled card's mana value.

Blazing Shoal

You may exile a red card with mana value X from your hand rather than pay this spell's mana cost.
Target creature gets +X/+0 until end of turn.

Arboretum Elemental

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.)
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

March of the Machines

Each noncreature artifact is an artifact creature with power and toughness each equal to its mana value. (Equipment that's a creature can't equip a creature.)

Rush of Knowledge

Draw cards equal to the highest mana value among permanents you control.

It of the Horrid Swarm

Emerge {6}{G} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, create two 1/1 green Insect creature tokens.

Metalwork Colossus

This spell costs {X} less to cast, where X is the total mana value of noncreature artifacts you control.
Sacrifice two artifacts: Return Metalwork Colossus from your graveyard to your hand.

Icebreaker Kraken

This spell costs {1} less to cast for each snow land you control.
When Icebreaker Kraken enters, artifacts and creatures target opponent controls don't untap during that player's next untap step.
Return three snow lands you control to their owner's hand: Return Icebreaker Kraken to its owner's hand.

Scornful Egotist

Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Spring Cleaning

Destroy target enchantment. Clash with an opponent. If you win, destroy all enchantments your opponents control. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Recross the Paths

Reveal cards from the top of your library until you reveal a land card. Put that card onto the battlefield and the rest on the bottom of your library in any order. Clash with an opponent. If you win, return Recross the Paths to its owner's hand. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Titania's Song

Each noncreature artifact loses all abilities and becomes an artifact creature with power and toughness each equal to its mana value. If Titania's Song leaves the battlefield, this effect continues until end of turn.

Primeval Protector

This spell costs {1} less to cast for each creature your opponents control.
When Primeval Protector enters, put a +1/+1 counter on each other creature you control.

Living Lore

As Living Lore enters, exile an instant or sorcery card from your graveyard.
Living Lore's power and toughness are each equal to the exiled card's mana value.
Whenever Living Lore deals combat damage, you may sacrifice it. If you do, you may cast the exiled card without paying its mana cost.

Ugin's Insight

Scry X, where X is the highest mana value among permanents you control, then draw three cards.

The Pride of Hull Clade

This spell costs {X} less to cast, where X is the total toughness of creatures you control.
Defender
{2}{U}{U}: Until end of turn, target creature you control gets +1/+0, gains "Whenever this creature deals combat damage to a player, draw cards equal to its toughness," and can attack as though it didn't have defender.

Electrodominance

Electrodominance deals X damage to any target. You may cast a spell with mana value X or less from your hand without paying its mana cost.

Scattering Stroke

Counter target spell. Clash with an opponent. If you win, at the beginning of your next main phase, you may add an amount of {C} equal to that spell's mana value. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Shadow of Mortality

If your life total is less than your starting life total, this spell costs {X} less to cast, where X is the difference.

Conduit of Ruin

When you cast this spell, you may search your library for a colorless creature card with mana value 7 or greater, reveal it, then shuffle and put that card on top.
The first creature spell you cast each turn costs {2} less to cast.

Niambi, Esteemed Speaker

Flash
When Niambi, Esteemed Speaker enters, you may return another target creature you control to its owner's hand. If you do, you gain life equal to that creature's mana value.
{1}{W}{U}, {T}, Discard a legendary card: Draw two cards.

Dispersal Shield

Counter target spell if its mana value is less than or equal to the highest mana value among permanents you control.

Heretic's Punishment

{3}{R}: Choose any target, then mill three cards. Heretic's Punishment deals damage to that permanent or player equal to the highest mana value among the milled cards.

Ghalta, Primal Hunger

This spell costs {X} less to cast, where X is the total power of creatures you control.
Trample

In Search of Greatness

At the beginning of your upkeep, you may cast a permanent spell from your hand with mana value equal to 1 plus the highest mana value among other permanents you control without paying its mana cost. If you don't, scry 1.

Augury Adept

Whenever Augury Adept deals combat damage to a player, reveal the top card of your library and put that card into your hand. You gain life equal to its mana value.

Naya Soulbeast

When you cast this spell, each player reveals the top card of their library. Naya Soulbeast enters with X +1/+1 counters on it, where X is the total mana value of all cards revealed this way.
Trample

Deep-Sea Kraken

Deep-Sea Kraken can't be blocked.
Suspend 9—{2}{U} (Rather than cast this card from your hand, you may pay {2}{U} and exile it with nine time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)
Whenever an opponent casts a spell, if Deep-Sea Kraken is suspended, remove a time counter from it.

Energy Tap

Tap target untapped creature you control. If you do, add an amount of {C} equal to that creature's mana value.

Homarid Spawning Bed

{1}{U}{U}, Sacrifice a blue creature: Create X 1/1 blue Camarid creature tokens, where X is the sacrificed creature's mana value.

Ayara, Furnace Queen

At the beginning of combat on your turn, return up to one target artifact or creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step.

Ayara, Widow of the Realm

{T}, Sacrifice another creature or artifact: Ayara, Widow of the Realm deals X damage to target opponent or battle and you gain X life, where X is the sacrificed permanent's mana value.
{5}{R/P}: Transform Ayara. Activate only as a sorcery. ({R/P} can be paid with either {R} or 2 life.)

Ayara, Widow of the Realm // Ayara, Furnace Queen

Necropolis

Defender (This creature can't attack.)
Exile a creature card from your graveyard: Put X +0/+1 counters on Necropolis, where X is the exiled card's mana value.

Autochthon Wurm

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.)
Trample

Metamorphosis

As an additional cost to cast this spell, sacrifice a creature.
Add X mana of any one color, where X is 1 plus the sacrificed creature's mana value. Spend this mana only to cast creature spells.

Interpret the Signs

Scry 3, then reveal the top card of your library. Draw cards equal to that card's mana value. (To scry 3, look at the top three cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Lashweed Lurker

Emerge {5}{G}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, you may put target nonland permanent on top of its owner's library.

Artifact Mutation

Destroy target artifact. It can't be regenerated. Create X 1/1 green Saproling creature tokens, where X is that artifact's mana value.

Dragon Scales

Enchant creature
Enchanted creature gets +1/+2 and has vigilance.
When a creature with mana value 6 or greater enters, you may return Dragon Scales from your graveyard to the battlefield attached to that creature.

Kalemne, Disciple of Iroas

Double strike, vigilance
Whenever you cast a creature spell with mana value 5 or greater, you get an experience counter.
Kalemne, Disciple of Iroas gets +1/+1 for each experience counter you have.

Animate Artifact

Enchant artifact
As long as enchanted artifact isn't a creature, it's an artifact creature with power and toughness each equal to its mana value.

Spark of Creativity

Choose target creature. Exile the top card of your library. You may have Spark of Creativity deal damage to that creature equal to the exiled card's mana value. If you don't, you may play that card until end of turn.

Draco

Domain — This spell costs {2} less to cast for each basic land type among lands you control.
Flying
Domain — At the beginning of your upkeep, sacrifice Draco unless you pay {10}. This cost is reduced by {2} for each basic land type among lands you control.

Decimator of the Provinces

Emerge {6}{G}{G}{G} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, creatures you control get +2/+2 and gain trample until end of turn.
Trample, haste

Spellbound Dragon

Flying
Whenever Spellbound Dragon attacks, draw a card, then discard a card. Spellbound Dragon gets +X/+0 until end of turn, where X is the discarded card's mana value.

Drownyard Behemoth

Flash (You may cast this spell any time you could cast an instant.)
Emerge {7}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
Drownyard Behemoth has hexproof as long as it entered this turn.