Hall of Storm Giants

If you control two or more other lands, Hall of Storm Giants enters tapped.
{T}: Add {U}.
{5}{U}: Until end of turn, Hall of Storm Giants becomes a 7/7 blue Giant creature with ward {3}. It's still a land. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)

Marble Priest

All Walls able to block Marble Priest do so.
Prevent all combat damage that would be dealt to Marble Priest by Walls.

Wall of Vapor

Defender (This creature can't attack.)
Prevent all damage that would be dealt to Wall of Vapor by creatures it's blocking.

Modify Memory

Exchange control of two target creatures controlled by different players. If you control neither creature, draw three cards.

Wandering Fumarole

Wandering Fumarole enters tapped.
{T}: Add {U} or {R}.
{2}{U}{R}: Until end of turn, Wandering Fumarole becomes a 1/4 blue and red Elemental creature with "{0}: Switch this creature's power and toughness until end of turn." It's still a land.

Juggernaut

Juggernaut attacks each combat if able.
Juggernaut can't be blocked by Walls.

Wall of Kelp

Defender (This creature can't attack.)
{U}{U}, {T}: Create a 0/1 blue Plant Wall creature token with defender named Kelp.

Twisted Image

Switch target creature's power and toughness until end of turn.
Draw a card.

Reverse the Polarity

Choose one —
• Counter all other spells.
• Switch each creature's power and toughness until end of turn.
• Creatures can't be blocked this turn.

Mannichi, the Fevered Dream

{1}{R}: Switch each creature's power and toughness until end of turn.

Deep Freeze

Enchant creature
Enchanted creature has base power and toughness 0/4, has defender, loses all other abilities, and is a blue Wall in addition to its other colors and types.

Chromeshell Crab

Morph {4}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Chromeshell Crab is turned face up, you may exchange control of target creature you control and target creature an opponent controls.

Wall of Water

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

Pitchstone Wall

Defender (This creature can't attack.)
Whenever you discard a card, you may sacrifice Pitchstone Wall. If you do, return the discarded card from your graveyard to your hand.

Sudden Substitution

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Exchange control of target noncreature spell and target creature. Then the spell's controller may choose new targets for it.

Merfolk Thaumaturgist

{T}: Switch target creature's power and toughness until end of turn.

Tunnel

Destroy target Wall. It can't be regenerated.

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Wall of Dust

Defender (This creature can't attack.)
Whenever Wall of Dust blocks a creature, that creature can't attack during its controller's next turn.

Djinn of Infinite Deceits

Flying
{T}: Exchange control of two target nonlegendary creatures. You can't activate this ability during combat.

Sindbad

{T}: Draw a card and reveal it. If it isn't a land card, discard it.

Glyph of Destruction

Target blocking Wall you control gets +10/+0 until end of combat. Prevent all damage that would be dealt to it this turn. Destroy it at the beginning of the next end step.

Quicksilver Wall

Defender (This creature can't attack.)
{4}: Return Quicksilver Wall to its owner's hand. Any player may activate this ability.

Wall of Fire

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

Daring Thief

Inspired — Whenever Daring Thief becomes untapped, you may exchange control of target nonland permanent you control and target permanent an opponent controls that shares a card type with it.

Wall of Diffusion

Defender (This creature can't attack.)
Wall of Diffusion can block creatures with shadow as though Wall of Diffusion had shadow.

Switcheroo

Exchange control of two target creatures.

Wall of Runes

Defender (This creature can't attack.)
When Wall of Runes enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Tower of Coireall

{T}: Target creature can't be blocked by Walls this turn.

Cultural Exchange

Choose any number of creatures target player controls. Choose the same number of creatures another target player controls. Those players exchange control of those creatures. (This effect lasts indefinitely.)

Surveyor's Scope

{T}, Exile Surveyor's Scope: Search your library for up to X basic land cards, where X is the number of players who control at least two more lands than you. Put those cards onto the battlefield, then shuffle.

Invent

Search your library for an instant card and/or a sorcery card, reveal them, put them into your hand, then shuffle.

Invert

Switch the power and toughness of each of up to two target creatures until end of turn.

Invert // Invent

Dwarven Thaumaturgist

Arcane Adaptation

As Arcane Adaptation enters, choose a creature type.
Creatures you control are the chosen type in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

Glyph of Delusion

Put X glyph counters on target creature that target Wall blocked this turn, where X is the power of that blocked creature. The creature gains "This creature doesn't untap during your untap step if it has a glyph counter on it" and "At the beginning of your upkeep, remove a glyph counter from this creature."

Siege Dragon

Flying
When Siege Dragon enters, destroy all Walls your opponents control.
Whenever Siege Dragon attacks, if defending player controls no Walls, it deals 2 damage to each creature without flying that player controls.

Role Reversal

Exchange control of two target permanents that share a permanent type.

Ali Baba

Geralf, Visionary Stitcher

Zombies you control have flying.
{U}, {T}, Sacrifice another nontoken creature: Create an X/X blue Zombie creature token, where X is the sacrificed creature's toughness.

Wall of Tears

Defender (This creature can't attack.)
Whenever Wall of Tears blocks a creature, return that creature to its owner's hand at end of combat.

Leyline of Transformation

If Leyline of Transformation is in your opening hand, you may begin the game with it on the battlefield.
As Leyline of Transformation enters, choose a creature type.
Creatures you control are the chosen type in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

Den of the Bugbear

If you control two or more other lands, Den of the Bugbear enters tapped.
{T}: Add {R}.
{3}{R}: Until end of turn, Den of the Bugbear becomes a 3/2 red Goblin creature with "Whenever this creature attacks, create a 1/1 red Goblin creature token that's tapped and attacking." It's still a land.

Wall of Frost

Defender
Whenever Wall of Frost blocks a creature, that creature doesn't untap during its controller's next untap step.

Wall of Stolen Identity

You may have Wall of Stolen Identity enter as a copy of any creature on the battlefield, except it's a Wall in addition to its other types and has defender. When you do, tap the copied creature and it doesn't untap during its controller's untap step for as long as you control Wall of Stolen Identity.