Boros Locket

{T}: Add {R} or {W}.
{R/W}{R/W}{R/W}{R/W}, {T}, Sacrifice Boros Locket: Draw two cards.

Boros Cluestone

{T}: Add {R} or {W}.
{R}{W}, {T}, Sacrifice Boros Cluestone: Draw a card.

Battlefield Forge

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

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Desert

{T}: Add {C}.
{T}: Desert deals 1 damage to target attacking creature. Activate only during the end of combat step.

Skewer the Critics

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Skewer the Critics deals 3 damage to any target.

Spark Trooper

Trample, lifelink, haste
At the beginning of the end step, sacrifice Spark Trooper.

Warleader's Helix

Warleader's Helix deals 4 damage to any target and you gain 4 life.

Molten Rain

Destroy target land. If that land was nonbasic, Molten Rain deals 2 damage to the land's controller.

Temple of Triumph

Temple of Triumph enters tapped.
When Temple of Triumph enters, scry 1.
{T}: Add {R} or {W}.

Sacred Foundry

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

Mountain

Boros Reckoner

Whenever Boros Reckoner is dealt damage, it deals that much damage to any target.
{R/W}: Boros Reckoner gains first strike 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.

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

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.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Plains

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice Ball Lightning.