Mardu Skullhunter

Mardu Skullhunter enters tapped.
Raid — When Mardu Skullhunter enters, if you attacked this turn, target opponent discards a card.

Mardu Ascendancy

Whenever a nontoken creature you control attacks, create a 1/1 red Goblin creature token that's tapped and attacking.
Sacrifice Mardu Ascendancy: Creatures you control get +0/+3 until end of turn.

Bloodfell Caves

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {R}.

Mardu Warshrieker

Raid — When Mardu Warshrieker enters, if you attacked this turn, add {R}{W}{B}.

Mountain

Swamp

Wind-Scarred Crag

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {W}.

Arrow Storm

Arrow Storm deals 4 damage to any target.
Raid — If you attacked this turn, instead Arrow Storm deals 5 damage to that permanent or player and the damage can't be prevented.

Plains

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Canyon Lurkers

Morph {3}{R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Valley Dasher

Haste
Valley Dasher attacks each combat if able.

Trumpet Blast

Attacking creatures get +2/+0 until end of turn.

Timely Hordemate

Raid — When Timely Hordemate enters, if you attacked this turn, return target creature card with mana value 2 or less from your graveyard to the battlefield.

Mardu Hordechief

Raid — When Mardu Hordechief enters, if you attacked this turn, create a 1/1 white Warrior creature token.