Manabarbs

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

Peregrine Mask

Equipped creature has defender, flying, and first strike.
Equip {2}

Izzet Signet

Sun Droplet

Whenever you're dealt damage, put that many charge counters on Sun Droplet.
At the beginning of each upkeep, you may remove a charge counter from Sun Droplet. If you do, you gain 1 life.

Sparkhunter Masticore

As an additional cost to cast this spell, discard a card.
Protection from planeswalkers
{1}: Sparkhunter Masticore deals 1 damage to target planeswalker.
{3}: Sparkhunter Masticore gains indestructible until end of turn.

Citadel of Pain

At the beginning of each player's end step, Citadel of Pain deals X damage to that player, where X is the number of untapped lands they control.

Mountain

Stuffy Doll

Indestructible
As Stuffy Doll enters, choose a player.
Whenever Stuffy Doll is dealt damage, it deals that much damage to the chosen player.
{T}: Stuffy Doll deals 1 damage to itself.

Mana Maze

Players can't cast spells that share a color with the spell most recently cast this turn.

Iron Myr

Island

Izzet Boilerworks

Izzet Boilerworks enters tapped.
When Izzet Boilerworks enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

Mana Cache

At the beginning of each player's end step, put a charge counter on Mana Cache for each untapped land that player controls.
Remove a charge counter from Mana Cache: Add {C}. Any player may activate this ability but only during their turn before the end step.

Creepy Doll

Indestructible
Whenever Creepy Doll deals combat damage to a creature, flip a coin. If you win the flip, destroy that creature.