Steam Vines

Enchant land
When enchanted land becomes tapped, destroy it and Steam Vines deals 1 damage to that land's controller. That player attaches Steam Vines to a land of their choice.

Spiteful Repossession

Spiteful Repossession deals damage to each opponent who controls more lands than you equal to the difference. Then create a number of Treasure tokens equal to the damage dealt this way.

Ankh of Mishra

Whenever a land enters, Ankh of Mishra deals 2 damage to that land's controller.

Rivalry

At the beginning of each player's upkeep, if that player controls more lands than each other player, Rivalry deals 2 damage to them.

Ruinous Minotaur

Whenever Ruinous Minotaur deals damage to an opponent, sacrifice a land.

Power Surge

At the beginning of each player's upkeep, Power Surge deals X damage to that player, where X is the number of untapped lands they controlled at the beginning of this turn.

Hurloon Shaman

When Hurloon Shaman dies, each player sacrifices a land.

Mox Opal

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.

Orcish Mine

Enchant land
Orcish Mine enters with three ore counters on it.
At the beginning of your upkeep and whenever enchanted land becomes tapped, remove an ore counter from Orcish Mine.
When the last ore counter is removed from Orcish Mine, destroy enchanted land and Orcish Mine deals 2 damage to that land's controller.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Ruby Medallion

Red spells you cast cost {1} less to cast.

Aether Vial

At the beginning of your upkeep, you may put a charge counter on Aether Vial.
{T}: You may put a creature card with mana value equal to the number of charge counters on Aether Vial from your hand onto the battlefield.

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Chrome Mox

Imprint — When Chrome Mox enters, you may exile a nonartifact, nonland card from your hand.
{T}: Add one mana of any of the exiled card's colors.

Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Zo-Zu the Punisher

Whenever a land enters, Zo-Zu the Punisher deals 2 damage to that land's controller.

Lava Blister

Destroy target nonbasic land unless its controller has Lava Blister deal 6 damage to them.