Prevent all combat damage that would be dealt this turn.

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Hull Breach

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Destroy target artifact and target enchantment.

Cleansing Beam

Radiance — Cleansing Beam deals 2 damage to target creature and each other creature that shares a color with it.

Magmaquake

Magmaquake deals X damage to each creature without flying and each planeswalker.

Hyrax Tower Scout

When Hyrax Tower Scout enters, untap target creature.

Spiteful Prankster

During your turn, Spiteful Prankster has first strike.
Whenever another creature dies, Spiteful Prankster deals 1 damage to target player or planeswalker.

Gruul Signet

Snapping Sailback

Flash
Enrage — Whenever Snapping Sailback is dealt damage, put a +1/+1 counter on it. (It must survive the damage to get the counter.)

Purifying Dragon

Flying
Whenever Purifying Dragon attacks, it deals 1 damage to target creature defending player controls. If that creature is a Zombie, Purifying Dragon deals 2 damage to it instead.

Grave Bramble

Mortal's Resolve

Target creature gets +1/+1 and gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Rolling Temblor

Rolling Temblor deals 2 damage to each creature without flying.
Flashback {4}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sun-Crowned Hunters

Enrage — Whenever Sun-Crowned Hunters is dealt damage, it deals 3 damage to target opponent or planeswalker.

Soul-Guide Lantern

When Soul-Guide Lantern enters, exile target card from a graveyard.
{T}, Sacrifice Soul-Guide Lantern: Exile each opponent's graveyard.
{1}, {T}, Sacrifice Soul-Guide Lantern: Draw a card.

Saber Ants

Whenever Saber Ants is dealt damage, you may create that many 1/1 green Insect creature tokens.

Irencrag Pyromancer

Whenever you draw your second card each turn, Irencrag Pyromancer deals 3 damage to any target.

Scavenging Ooze

{G}: Exile target card from a graveyard. If it was a creature card, put a +1/+1 counter on Scavenging Ooze and you gain 1 life.

Vrondiss, Rage of Ancients

Enrage — Whenever Vrondiss, Rage of Ancients is dealt damage, you may create a 5/4 red and green Dragon Spirit creature token with "When this creature deals damage, sacrifice it."
Whenever you roll one or more dice, you may have Vrondiss deal 1 damage to itself.

Cinderclasm

Kicker {R} (You may pay an additional {R} as you cast this spell.)
Cinderclasm deals 1 damage to each creature. If it was kicked, it deals 2 damage to each creature instead.

Dingus Staff

Whenever a creature dies, Dingus Staff deals 2 damage to that creature's controller.

Gimli, Counter of Kills

Trample
Whenever a creature an opponent controls dies, Gimli, Counter of Kills deals 1 damage to that creature's controller.

Explore

You may play an additional land this turn.
Draw a card.

Green Dragon

Flying
Poison Breath — When Green Dragon enters, until end of turn, whenever a creature an opponent controls is dealt damage, destroy it.

Reclamation Sage

When Reclamation Sage enters, you may destroy target artifact or enchantment.

Into the Fire

Choose one —
• Into the Fire deals 2 damage to each creature, planeswalker, and battle.
• Put any number of cards from your hand on the bottom of your library, then draw that many cards plus one.

Fiendlash

Equipped creature gets +2/+0 and has reach.
Whenever equipped creature is dealt damage, it deals damage equal to its power to target player or planeswalker.
Equip {2}{R}

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Sporeweb Weaver

Reach, hexproof from blue
Whenever Sporeweb Weaver is dealt damage, you gain 1 life and create a 1/1 green Saproling creature token.

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

Disrupt Decorum

Goad all creatures you don't control. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Volcanic Fallout

This spell can't be countered.
Volcanic Fallout deals 2 damage to each creature and each player.

Pyroclasm

Pyroclasm deals 2 damage to each creature.

Aether Flash

Whenever a creature enters, Aether Flash deals 2 damage to it.

Cacophodon

Enrage — Whenever Cacophodon is dealt damage, untap target permanent.

Tumble

Tumble deals 6 damage to each creature with flying.

Rough

Rough deals 2 damage to each creature without flying.

Rough // Tumble

Decimate

Destroy target artifact, target creature, target enchantment, and target land. (You can't cast this spell unless you have legal choices for all its targets.)

Forest

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.

Kazuul, Tyrant of the Cliffs

Whenever a creature an opponent controls attacks, if you're the defending player, create a 3/3 red Ogre creature token unless that creature's controller pays {3}.

Mountain

Repercussion

Whenever a creature is dealt damage, Repercussion deals that much damage to that creature's controller.

Whipflare

Whipflare deals 2 damage to each nonartifact creature.

Flame Sweep

Flame Sweep deals 2 damage to each creature except for creatures you control with flying.

Overgrown Armasaur

Enrage — Whenever Overgrown Armasaur is dealt damage, create a 1/1 green Saproling creature token.

Refraction Elemental

Ward—Pay 2 life.
Whenever you cast a spell, Refraction Elemental deals 2 damage to each opponent.

Invasion of Karsus

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Karsus enters, it deals 3 damage to each creature and each planeswalker.

Invasion of Karsus // Refraction Elemental

Shock

Steam Blast

Steam Blast deals 2 damage to each creature and each player.

Gift of the Viper

Put a +1/+1 counter, a reach counter, and a deathtouch counter on target creature. Untap it.

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Haruspex

Rapacious Hunger — Whenever another creature dies, put a +1/+1 counter on Haruspex.
Devouring Monster — {T}, Remove X +1/+1 counters from Haruspex: Add X mana of any one color.

Basilisk Collar

Equipped creature has deathtouch and lifelink.
Equip {2}

Arcane Signet

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

Fertile Ground

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Coronation of Chaos

Up to three target creatures can't block this turn. Goad them. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Hansk, Slayer Zealot

At the beginning of your upkeep, target opponent creates three Walker tokens. (They're 2/2 black Zombie creatures.)
{T}: Hansk, Slayer Zealot deals 2 damage to target creature.
Whenever a Zombie an opponent controls dies, draw a card.

Reap

Return up to X target cards from your graveyard to your hand, where X is the number of black permanents target opponent controls as you cast this spell.

Deep-Slumber Titan

Deep-Slumber Titan enters tapped.
Deep-Slumber Titan doesn't untap during your untap step.
Whenever Deep-Slumber Titan is dealt damage, untap it.

Evolving Wilds

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

Talisman of Impulse

{T}: Add {C}.
{T}: Add {R} or {G}. Talisman of Impulse deals 1 damage to you.

Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Starstorm

Starstorm deals X damage to each creature.
Cycling {3} ({3}, Discard this card: Draw a card.)

Donna Noble

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
Whenever Donna or a creature it's paired with is dealt damage, Donna deals that much damage to target opponent.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Vampires' Vengeance

Vampires' Vengeance deals 2 damage to each non-Vampire creature. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Ranging Raptors

Enrage — Whenever Ranging Raptors is dealt damage, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.