Mana dubblers

Mana Flare

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Damage doublers

Bloodletter of Aclazotz

Flying
If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)

Ramp

Ignoble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {B}, {R}, or {G}.

Prismatic Vista

{T}, Pay 1 life, Sacrifice Prismatic Vista: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Valakut Stoneforge

Valakut Stoneforge enters the battlefield tapped.
{T}: Add {R}.

Draw

Valakut Awakening

Put any number of cards from your hand on the bottom of your library, then draw that many cards plus one.

Valakut Awakening // Valakut Stoneforge

Empowerment

Tyvar's Stand

Target creature you control gets +X/+X and gains hexproof and indestructible until end of turn. (A creature with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Untap

Patriar's Seal

{T}: Add one mana of any color.
{1}, {T}: Untap target legendary creature you control.

Spot removal

Orcish Bowmasters

Flash
When Orcish Bowmasters enters the battlefield and whenever an opponent draws a card except the first one they draw in each of their draw steps, Orcish Bowmasters deals 1 damage to any target. Then amass Orcs 1.

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Umbral Mantle

Equipped creature has "{3}, {Q}: This creature gets +2/+2 until end of turn." ({Q} is the untap symbol.)
Equip {0}

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Grave Hate

Bojuka Bog

Bojuka Bog enters the battlefield tapped.
When Bojuka Bog enters the battlefield, exile target player's graveyard.
{T}: Add {B}.

Land

Bayou

Myriad Landscape

Myriad Landscape enters the battlefield tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Manasink

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent or discards a card.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Burn compen

Horizon Stone

If you would lose unspent mana, that mana becomes colorless instead.

Swamp

Extra mana

Magus of the Vineyard

At the beginning of each player's precombat main phase, that player adds {G}{G}.

Drain

Polluted Bonds

Whenever a land enters the battlefield under an opponent's control, that player loses 2 life and you gain 2 life.

Burn

Burning Earth

Whenever a player taps a nonbasic land for mana, Burning Earth deals 1 damage to that player.

Keeper of Progenitus

Whenever a player taps a Mountain, Forest, or Plains for mana, that player adds one mana of any type that land produced.

Klothys, God of Destiny

Indestructible
As long as your devotion to red and green is less than seven, Klothys isn't a creature.
At the beginning of your precombat main phase, exile target card from a graveyard. If it was a land card, add {R} or {G}. Otherwise, you gain 2 life and Klothys deals 2 damage to each opponent.

Heartless Hidetsugu

{T}: Heartless Hidetsugu deals damage to each player equal to half that player's life total, rounded down.

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Command Tower

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

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Dictate of Karametra

Flash
Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Harsh Mentor

Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, Harsh Mentor deals 2 damage to that player.

Tangleroot

Whenever a player casts a creature spell, that player adds {G}.

Badlands

Tear Asunder

Kicker {1}{B} (You may pay an additional {1}{B} as you cast this spell.)
Exile target artifact or enchantment. If this spell was kicked, exile target nonland permanent instead.

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Primal Order

At the beginning of each player's upkeep, Primal Order deals damage to that player equal to the number of nonbasic lands they control.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Control

War's Toll

Whenever an opponent taps a land for mana, tap all lands that player controls.
If a creature an opponent controls attacks, all creatures that opponent controls attack if able.

Birds of Paradise

Exocrine

Ravenous (This creature enters the battlefield with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Bio-plasmic Barrage — When Exocrine enters the battlefield, it deals X damage to each player and each other creature.

Price of Progress

Price of Progress deals damage to each player equal to twice the number of nonbasic lands that player controls.

Arcane Signet

Forest

Magus of the Candelabra

Taiga

Dig Up

Cleave {1}{B}{B}{G} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Search your library for a [basic land] card, [reveal it,] put it into your hand, then shuffle.

Ob Nixilis, Captive Kingpin

Flying, trample
Whenever one or more opponents each lose exactly 1 life, put a +1/+1 counter on Ob Nixilis, Captive Kingpin. Exile the top card of your library. Until your next end step, you may play that card.

Bloodstained Mire

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Eladamri's Vineyard

Crawling Barrens

{T}: Add {C}.
{4}: Put two +1/+1 counters on Crawling Barrens. Then you may have it become a 0/0 Elemental creature until end of turn. It's still a land.

Destiny Spinner

Creature and enchantment spells you control can't be countered.
{3}{G}: Target land you control becomes an X/X Elemental creature with trample and haste until end of turn, where X is the number of enchantments you control. It's still a land.

Verdant Catacombs

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Zhur-Taa Ancient

Ziatora's Proving Ground

({T}: Add {B}, {R}, or {G}.)
Ziatora's Proving Ground enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Staff of Domination

{1}: Untap Staff of Domination.
{2}, {T}: You gain 1 life.
{3}, {T}: Untap target creature.
{4}, {T}: Tap target creature.
{5}, {T}: Draw a card.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Yurlok of Scorch Thrash

Vigilance
A player losing unspent mana causes that player to lose that much life.
{1}, {T}: Each player adds {B}{R}{G}.

Spellshock

Whenever a player casts a spell, Spellshock deals 2 damage to that player.

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Sword of the Paruns

As long as equipped creature is tapped, tapped creatures you control get +2/+0.
As long as equipped creature is untapped, untapped creatures you control get +0/+2.
{3}: You may tap or untap equipped creature.
Equip {3}

Destructive Revelry

Destroy target artifact or enchantment. Destructive Revelry deals 2 damage to that permanent's controller.

Belbe, Corrupted Observer

At the beginning of each player's postcombat main phase, that player adds {C}{C} for each of your opponents who lost life this turn. (Damage causes loss of life.)

Heartbeat of Spring

Zhur-Taa Druid

{T}: Add {G}.
Whenever you tap Zhur-Taa Druid for mana, it deals 1 damage to each opponent.

Immolation Shaman

Whenever an opponent activates an ability of an artifact, creature, or land that isn't a mana ability, Immolation Shaman deals 1 damage to that player.
{3}{R}{R}: Immolation Shaman gets +3/+3 and gains menace until end of turn.

Sol Ring

Cindervines

Whenever an opponent casts a noncreature spell, Cindervines deals 1 damage to that player.
{1}, Sacrifice Cindervines: Destroy target artifact or enchantment. Cindervines deals 2 damage to that permanent's controller.

The Scorpion God

Whenever a creature with a -1/-1 counter on it dies, draw a card.
{1}{B}{R}: Put a -1/-1 counter on another target creature.
When The Scorpion God dies, return it to its owner's hand at the beginning of the next end step.

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Saryth, the Viper's Fang

Other tapped creatures you control have deathtouch.
Other untapped creatures you control have hexproof.
{1}, {T}: Untap another target creature or land you control.

Wooded Foothills

{T}, Pay 1 life, Sacrifice Wooded Foothills: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Temple of Power

(Transforms from Ojer Axonil, Deepest Might.)
{T}: Add {R}.
{2}{R}, {T}: Transform Temple of Power. Activate only if red sources you controlled dealt 4 or more noncombat damage this turn and only as a sorcery.

Ojer Axonil, Deepest Might

Trample
If a red source you control would deal an amount of noncombat damage less than Ojer Axonil's power to an opponent, that source deals damage equal to Ojer Axonil's power instead.
When Ojer Axonil dies, return it to the battlefield tapped and transformed under its owner's control.

Ojer Axonil, Deepest Might // Temple of Power

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Xantcha, Sleeper Agent

Xantcha, Sleeper Agent enters the battlefield under the control of an opponent of your choice.
Xantcha attacks each combat if able and can't attack its owner or planeswalkers its owner controls.
{3}: Xantcha's controller loses 2 life and you draw a card. Any player may activate this ability.

Runic Armasaur

Whenever an opponent activates an ability of a creature or land that isn't a mana ability, you may draw a card.

Spires of Orazca

(Transforms from Thaumatic Compass.)
{T}: Add {C}.
{T}: Untap target attacking creature an opponent controls and remove it from combat.

Thaumatic Compass

{3}, {T}: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
At the beginning of your end step, if you control seven or more lands, transform Thaumatic Compass.

Thaumatic Compass // Spires of Orazca

Archfiend of Despair

Flying
Your opponents can't gain life.
At the beginning of each end step, each opponent loses life equal to the life that player lost this turn. (Damage causes loss of life.)

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Mountain

Nyxbloom Ancient

Trample
If you tap a permanent for mana, it produces three times as much of that mana instead.

Agatha of the Vile Cauldron

Activated abilities of creatures you control cost {X} less to activate, where X is Agatha of the Vile Cauldron's power. This effect can't reduce the mana in that cost to less than one mana.
{4}{R}{G}: Other creatures you control get +1/+1 and gain trample and haste until end of turn.

Gwenna, Eyes of Gaea

{T}: Add two mana in any combination of colors. Spend this mana only to cast creature spells or activate abilities of a creature or creature card.
Whenever you cast a creature spell with power 5 or greater, put a +1/+1 counter on Gwenna, Eyes of Gaea and untap it.

Asceticism

Creatures you control have hexproof.
{1}{G}: Regenerate target creature. (The next time it would be destroyed, instead tap it, remove it from combat, and heal all damage on it.)

Roiling Vortex

At the beginning of each player's upkeep, Roiling Vortex deals 1 damage to them.
Whenever a player casts a spell, if no mana was spent to cast that spell, Roiling Vortex deals 5 damage to that player.
{R}: Your opponents can't gain life this turn.

Vilis, Broker of Blood

Flying
{B}, Pay 2 life: Target creature gets -1/-1 until end of turn.
Whenever you lose life, draw that many cards. (Damage causes loss of life.)

Havoc Festival

Players can't gain life.
At the beginning of each player's upkeep, that player loses half their life, rounded up.

Leyline of Abundance

If Leyline of Abundance is in your opening hand, you may begin the game with it on the battlefield.
Whenever you tap a creature for mana, add an additional {G}.
{6}{G}{G}: Put a +1/+1 counter on each creature you control.