Havoc Festival

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

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Anguished Unmaking

Exile target nonland permanent. You lose 3 life.

Command Tower

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

Fervor

Creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Heartless Hidetsugu

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

God-Eternal Rhonas

Deathtouch
When God-Eternal Rhonas enters, double the power of each other creature you control until end of turn. Those creatures gain vigilance until end of turn.
When God-Eternal Rhonas dies or is put into exile from the battlefield, you may put it into its owner's library third from the top.

Dictate of the Twin Gods

Flash
If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Banefire

Banefire deals X damage to any target.
If X is 5 or more, this spell can't be countered and the damage can't be prevented.

Stuffy Doll

Indestructible
As Stuffy Doll enters, choose a player.
Whenever Stuffy Doll is dealt damage, it deals that much damage to the chosen player.
{T}: Stuffy Doll deals 1 damage to itself.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Overblaze

Each time target permanent would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.
Splice onto Arcane {2}{R}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Duelist's Heritage

Whenever one or more creatures attack, you may have target attacking creature gain double strike until end of turn.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters, you may pay 2 life. If you don't, it enters tapped.

Hammer of Purphoros

Creatures you control have haste.
{2}{R}, {T}, Sacrifice a land: Create a 3/3 colorless Golem enchantment artifact creature token.

Injury

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Injury deals 2 damage to target creature and 2 damage to target player or planeswalker.

Insult

Damage can't be prevented this turn. If a source you control would deal damage this turn, it deals double that damage instead.

Insult // Injury

Rootbound Crag

Rootbound Crag enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

In the Web of War

Whenever a creature you control enters, it gets +2/+0 and gains haste until end of turn.

Mortify

Canopy Vista

({T}: Add {G} or {W}.)
Canopy Vista enters tapped unless you control two or more basic lands.

Omnath, Locus of Rage

Landfall — Whenever a land you control enters, create a 5/5 red and green Elemental creature token.
Whenever Omnath, Locus of Rage or another Elemental you control dies, Omnath deals 3 damage to any target.

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Brushland

{T}: Add {C}.
{T}: Add {G} or {W}. Brushland deals 1 damage to you.

Austere Command

Choose two —
• Destroy all artifacts.
• Destroy all enchantments.
• Destroy all creatures with mana value 3 or less.
• Destroy all creatures with mana value 4 or greater.

Dictate of Karametra

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

Samut, Voice of Dissent

Flash
Double strike, vigilance, haste
Other creatures you control have haste.
{W}, {T}: Untap another target creature.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Gisela, Blade of Goldnight

Flying, first strike
If a source would deal damage to an opponent or a permanent an opponent controls, that source deals double that damage to that player or permanent instead.
If a source would deal damage to you or a permanent you control, prevent half that damage, rounded up.

Sol Ring

Basilisk Collar

Equipped creature has deathtouch and lifelink.
Equip {2}

Orzhov Signet

Whip of Erebos

Creatures you control have lifelink.
{2}{B}{B}, {T}: Return target creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step. If it would leave the battlefield, exile it instead of putting it anywhere else. Activate only as a sorcery.

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters tapped unless you control two or more basic lands.

Scheming Symmetry

Choose two target players. Each of them searches their library for a card, then shuffles and puts that card on top.

Swamp

Ogre Battledriver

Whenever another creature you control enters, that creature gets +2/+0 and gains haste until end of turn. (It can attack and {T} this turn.)

Furnace of Rath

If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

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.)

Star of Extinction

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

Shock

Knight of the Reliquary

Knight of the Reliquary gets +1/+1 for each land card in your graveyard.
{T}, Sacrifice a Forest or Plains: Search your library for a land card, put it onto the battlefield, then shuffle.

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Angelic Skirmisher

Flying
At the beginning of each combat, choose first strike, vigilance, or lifelink. Creatures you control gain that ability until end of turn.

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Golgari Signet

Arcane Signet

Stonehoof Chieftain

Trample, indestructible
Whenever another creature you control attacks, it gains trample and indestructible until end of turn.

Saskia the Unyielding

Vigilance, haste
As Saskia the Unyielding enters, choose a player.
Whenever a creature you control deals combat damage to a player, it deals that much damage to the chosen player.

Forest

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Zendikar Resurgent

Whenever you tap a land for mana, add one mana of any type that land produced. (The types of mana are white, blue, black, red, green, and colorless.)
Whenever you cast a creature spell, draw a card.

Kodama's Reach

Explosive Vegetation

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Bitter Feud

As Bitter Feud enters, choose two players.
If a source controlled by one of the chosen players would deal damage to the other chosen player or a permanent that player controls, that source deals double that damage to that player or permanent instead.

Vindicate

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Mountain

Erebos, God of the Dead

Indestructible
As long as your devotion to black is less than five, Erebos isn't a creature. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
Your opponents can't gain life.
{1}{B}, Pay 2 life: Draw a card.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

Plains

Boros Signet

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Merciless Eviction

Choose one —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all planeswalkers.

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Rakdos Signet

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.)

Sower of Discord

Flying
As Sower of Discord enters, choose two players.
Whenever damage is dealt to one of the chosen players, the other chosen player also loses that much life.

Temple Garden

({T}: Add {G} or {W}.)
As Temple Garden enters, you may pay 2 life. If you don't, it enters tapped.

Karplusan Forest

{T}: Add {C}.
{T}: Add {R} or {G}. Karplusan Forest deals 1 damage to you.

Bow of Nylea

Attacking creatures you control have deathtouch.
{1}{G}, {T}: Choose one —
• Put a +1/+1 counter on target creature.
• Bow of Nylea deals 2 damage to target creature with flying.
• You gain 3 life.
• Put up to four target cards from your graveyard on the bottom of your library in any order.

Curse of Bloodletting

Enchant player
If a source would deal damage to enchanted player, it deals double that damage to that player instead.

Quest for Pure Flame

Whenever a source you control deals damage to an opponent, you may put a quest counter on Quest for Pure Flame.
Remove four quest counters from Quest for Pure Flame and sacrifice it: If any source you control would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.

Gratuitous Violence

If a creature you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Aurelia, the Warleader

Flying, vigilance, haste
Whenever Aurelia, the Warleader attacks for the first time each turn, untap all creatures you control. After this phase, there is an additional combat phase.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters, you may pay 2 life. If you don't, it enters tapped.

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters, you may pay 2 life. If you don't, it enters tapped.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. Caves of Koilos deals 1 damage to you.

Alabaster Mage

{1}{W}: Target creature you control gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)