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.

Neheb, the Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
At the beginning of each of your postcombat main phases, add {R} for each 1 life your opponents have lost this turn.

Opal Guardian

When an opponent casts a creature spell, if Opal Guardian is an enchantment, Opal Guardian becomes a 3/4 Gargoyle creature with flying and protection from red.

Sanctifier en-Vec

Protection from black and from red
When Sanctifier en-Vec enters, exile all cards that are black or red from all graveyards.
If a black or red permanent, spell, or card not on the battlefield would be put into a graveyard, exile it instead.

Crackle with Power

Crackle with Power deals five times X damage to each of up to X targets.

Tivadar of Thorn

First strike, protection from red
When Tivadar of Thorn enters, destroy target Goblin.

Imodane, the Pyrohammer

Whenever an instant or sorcery spell you control that targets only a single creature deals damage to that creature, Imodane deals that much damage to each opponent.

Chandra's Incinerator

This spell costs {X} less to cast, where X is the total amount of noncombat damage dealt to your opponents this turn.
Trample
Whenever a source you control deals noncombat damage to an opponent, Chandra's Incinerator deals that much damage to target creature or planeswalker that player controls.

Satyr Firedancer

Whenever an instant or sorcery spell you control deals damage to an opponent, Satyr Firedancer deals that much damage to target creature that player controls.

Wrathful Red Dragon

Flying
Whenever a Dragon you control is dealt damage, it deals that much damage to any target that isn't a Dragon.

Repercussion

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

Blazing Sunsteel

Equipped creature gets +1/+0 for each opponent you have.
Whenever equipped creature is dealt damage, it deals that much damage to any target.
Equip {4}

Guardian of the Guildpact

Kor Firewalker

Protection from red
Whenever a player casts a red spell, you may gain 1 life.

Auriok Champion

Protection from black and from red
Whenever another creature enters, you may gain 1 life.

Lavinia of the Tenth

Protection from red
When Lavinia of the Tenth enters, detain each nonland permanent your opponents control with mana value 4 or less. (Until your next turn, those permanents can't attack or block and their activated abilities can't be activated.)

Howlpack Avenger

Whenever a permanent you control is dealt damage, Howlpack Avenger deals that much damage to any target.
{1}{R}: Howlpack Avenger gets +2/+0 until end of turn.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Ill-Tempered Loner

Whenever Ill-Tempered Loner is dealt damage, it deals that much damage to any target.
{1}{R}: Ill-Tempered Loner gets +2/+0 until end of turn.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Ill-Tempered Loner // Howlpack Avenger

Pyrohemia

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pyrohemia.
{R}: Pyrohemia deals 1 damage to each creature and each player.

Blasphemous Act

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

Akroma, Angel of Wrath

Flying, first strike, vigilance, trample, haste, protection from black and from red

Vedalken Outlander

Reckless Rage

Reckless Rage deals 4 damage to target creature you don't control and 2 damage to target creature you control.

Disciples of the Inferno

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
If a noncreature source you control would deal damage to a creature, battle, or opponent, it deals that much damage plus 2 instead.

Invasion of Regatha

(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 Regatha enters, it deals 4 damage to another target battle or opponent and 1 damage to up to one target creature.

Invasion of Regatha // Disciples of the Inferno

Spiteful Sliver

Sliver creatures you control have "Whenever this creature is dealt damage, it deals that much damage to target player or planeswalker."

Mask of Law and Grace

Enchant creature
Enchanted creature has protection from black and from red.

Soltari Priest

Protection from red
Shadow (This creature can block or be blocked by only creatures with shadow.)

Ashling the Pilgrim

{1}{R}: Put a +1/+1 counter on Ashling the Pilgrim. If this is the third time this ability has resolved this turn, remove all +1/+1 counters from Ashling the Pilgrim, and it deals that much damage to each creature and each player.

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.)

Arcbond

Choose target creature. Whenever that creature is dealt damage this turn, it deals that much damage to each other creature and each player.

Paladin en-Vec

First strike, protection from black and from red (This creature deals combat damage before creatures without first strike. It can't be blocked, targeted, dealt damage, or enchanted by anything black or red.)

Wrathful Raptors

Trample
Whenever a Dinosaur you control is dealt damage, it deals that much damage to any target that isn't a Dinosaur.

Mystic Crusader

Protection from black and from red
Threshold — As long as seven or more cards are in your graveyard, Mystic Crusader gets +1/+1 and has flying.

Mogg Maniac

Whenever Mogg Maniac is dealt damage, it deals that much damage to target opponent or planeswalker.

Star of Extinction

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

Brash Taunter

Indestructible
Whenever Brash Taunter is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: Brash Taunter fights another target creature.

Crimson Acolyte

Protection from red
{W}: Target creature gains protection from red until end of turn.

Firesong and Sunspeaker

Red instant and sorcery spells you control have lifelink.
Whenever a white instant or sorcery spell causes you to gain life, Firesong and Sunspeaker deals 3 damage to target creature or player.

Akroma's Blessing

Choose a color. Creatures you control gain protection from the chosen color until end of turn.
Cycling {W} ({W}, Discard this card: Draw a card.)

Galina's Knight

Akroma's Memorial

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

Phyrexian Vindicator

Flying
If damage would be dealt to Phyrexian Vindicator, prevent that damage. When damage is prevented this way, Phyrexian Vindicator deals that much damage to any other target.

Sevinne, the Chronoclasm

Prevent all damage that would be dealt to Sevinne, the Chronoclasm.
Whenever you cast your first instant or sorcery spell from your graveyard each turn, copy that spell. You may choose new targets for the copy.