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.

Mishra's Bauble

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

Monastery Swiftspear

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Dragon's Rage Channeler

Whenever you cast a noncreature spell, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
Delirium — As long as there are four or more card types among cards in your graveyard, Dragon's Rage Channeler gets +2/+2, has flying, and attacks each combat if able.

Goblin Guide

Haste
Whenever Goblin Guide attacks, defending player reveals the top card of their library. If it's a land card, that player puts it into their hand.

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Sunbaked Canyon

{T}, Pay 1 life: Add {R} or {W}.
{1}, {T}, Sacrifice Sunbaked Canyon: Draw a card.

Wooded Foothills

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

Lava Spike

Lava Spike deals 3 damage to target player or planeswalker.

Lava Dart

Lava Dart deals 1 damage to any target.
Flashback—Sacrifice a Mountain. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Skullcrack

Players can't gain life this turn. Damage can't be prevented this turn. Skullcrack deals 3 damage to target player or planeswalker.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Stomping Ground

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

Atarka's Command

Choose two —
• Your opponents can't gain life this turn.
• Atarka's Command deals 3 damage to each opponent.
• You may put a land card from your hand onto the battlefield.
• Creatures you control get +1/+1 and gain reach until end of turn.

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.

Mountain

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Sacred Foundry

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