Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Unstable Mutation

Enchant creature
Enchanted creature gets +3/+3.
At the beginning of the upkeep of enchanted creature's controller, put a -1/-1 counter on that creature.

Gaseous Form

Enchant creature
Prevent all combat damage that would be dealt to and dealt by enchanted creature.

Braingeyser

Mahamoti Djinn

Flying (This creature can't be blocked except by creatures with flying or reach.)

Flood

{U}{U}: Tap target creature without flying.

Water Elemental

Crystal Rod

Whenever a player casts a blue spell, you may pay {1}. If you do, you gain 1 life.

Steal Artifact

Enchant artifact
You control enchanted artifact.

Stasis

Players skip their untap steps.
At the beginning of your upkeep, sacrifice Stasis unless you pay {U}.

Blue Mana Battery

{2}, {T}: Put a charge counter on Blue Mana Battery.
{T}, Remove any number of charge counters from Blue Mana Battery: Add {U}, then add an additional {U} for each charge counter removed this way.

Phantom Monster

Lifetap

Whenever a Forest an opponent controls becomes tapped, you gain 1 life.

Millstone

Siren's Call

Cast this spell only during an opponent's turn, before attackers are declared.
Creatures the active player controls attack this turn if able.
At the beginning of the next end step, destroy all non-Wall creatures that player controls that didn't attack this turn. Ignore this effect for each creature the player didn't control continuously since the beginning of the turn.

Power Leak

Enchant enchantment
At the beginning of the upkeep of enchanted enchantment's controller, that player may pay any amount of mana. Power Leak deals 2 damage to that player. Prevent X of that damage, where X is the amount of mana that player paid this way.

Wall of Water

Defender (This creature can't attack.)
{U}: Wall of Water gets +1/+0 until end of turn.

Apprentice Wizard

Unsummon

Return target creature to its owner's hand.

Wall of Air

Defender, flying (This creature can't attack, and it can block creatures with flying.)

Volcanic Eruption

Destroy X target Mountains. Volcanic Eruption deals damage to each creature and each player equal to the number of Mountains put into a graveyard this way.

Backfire

Enchant creature
Whenever enchanted creature deals damage to you, Backfire deals that much damage to that creature's controller.

Leviathan

Trample
Leviathan enters tapped and doesn't untap during your untap step.
At the beginning of your upkeep, you may sacrifice two Islands. If you do, untap Leviathan.
Leviathan can't attack unless you sacrifice two Islands. (This cost is paid as attackers are declared.)

Feedback

Enchant enchantment
At the beginning of the upkeep of enchanted enchantment's controller, Feedback deals 1 damage to that player.

Sunken City

At the beginning of your upkeep, sacrifice Sunken City unless you pay {U}{U}.
Blue creatures get +1/+1.

Counterspell

Blue Elemental Blast

Choose one —
• Counter target red spell.
• Destroy target red permanent.

Segovian Leviathan

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Island

Phantasmal Forces

Flying
At the beginning of your upkeep, sacrifice Phantasmal Forces unless you pay {U}.

Control Magic

Enchant creature
You control enchanted creature.

Library of Leng

You have no maximum hand size.
If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.

Lord of Atlantis

Other Merfolk get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

Merfolk of the Pearl Trident

Prodigal Sorcerer

{T}: Prodigal Sorcerer deals 1 damage to any target.

Drain Power

Target player activates a mana ability of each land they control. Then that player loses all unspent mana and you add the mana lost this way.