Pyroclasm

Pyroclasm deals 2 damage to each creature.

Mox Pearl

Auriok Champion

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

Mountain

Crimson Acolyte

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

Repercussion

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

Arid Mesa

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

Blasphemous Act

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

Plateau

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.

Sol Ring

Plains

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.)

Steam Blast

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

Kor Firewalker

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

Well of Lost Dreams

Whenever you gain life, you may pay {X}, where X is less than or equal to the amount of life you gained. If you do, draw X cards.

Varchild's War-Riders

Cumulative upkeep—Have an opponent create a 1/1 red Survivor creature token. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Trample; rampage 1 (Whenever this creature becomes blocked, it gets +1/+1 until end of turn for each creature blocking it beyond the first.)

Mox Diamond

If Mox Diamond would enter, you may discard a land card instead. If you do, put Mox Diamond onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add one mana of any color.