Boros Reckoner

Whenever this creature is dealt damage, it deals that much damage to any target.
{R/W}: This creature gains first strike until end of turn.

Rugged Prairie

{T}: Add {C}.
{R/W}, {T}: Add {R}{R}, {R}{W}, or {W}{W}.

Sacred Foundry

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

Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

Ghostfire Slice

Devoid (This card has no color.)
This spell costs {2} less to cast if an opponent controls a multicolored permanent.
Ghostfire Slice deals 4 damage to any target.

Mountain

Satyr Firedancer

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

Lightning Helix

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

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.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Chain Reaction

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

Phlage, Titan of Fire's Fury

When Phlage enters, sacrifice it unless it escaped.
Whenever Phlage enters or attacks, it deals 3 damage to any target and you gain 3 life.
Escape—{R}{R}{W}{W}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Hidetsugu's Second Rite

If target player has exactly 10 life, Hidetsugu's Second Rite deals 10 damage to that player.

Grab the Prize

As an additional cost to cast this spell, discard a card.
Draw two cards. If the discarded card wasn't a land card, Grab the Prize deals 2 damage to each opponent.

Intimidation Bolt

Intimidation Bolt deals 3 damage to target creature. Other creatures can't attack this turn.