Have

Psychic Membrane

Defender (This creature can't attack.)
Whenever Psychic Membrane blocks, you may draw a card.

Crenellated Wall

Defender (This creature can't attack.)
{T}: Target creature gets +0/+4 until end of turn.

Jeskai Barricade

Flash (You may cast this spell any time you could cast an instant.)
Defender
When Jeskai Barricade enters, you may return another target creature you control to its owner's hand.

Cathedral Membrane

({W/P} can be paid with either {W} or 2 life.)
Defender
When Cathedral Membrane dies during combat, it deals 6 damage to each creature it blocked this combat.

Guard Gomazoa

Defender, flying
Prevent all combat damage that would be dealt to Guard Gomazoa.

Doorkeeper

Defender
{2}{U}, {T}: Target player mills X cards, where X is the number of creatures you control with defender.

Aetherize

Return all attacking creatures to their owner's hand.

Sokrates, Athenian Teacher

Defender
Sokrates, Athenian Teacher has hexproof as long as it's untapped.
Sokratic Dialogue — {T}: Until end of turn, target creature gains "If this creature would deal combat damage to a player, prevent that damage. This creature's controller and that player each draw half that many cards, rounded down."

Negate

Austere Command

Choose two —
• Destroy all artifacts.
• Destroy all enchantments.
• Destroy all creatures with mana value 3 or less.
• Destroy all creatures with mana value 4 or greater.

Boros Garrison

Boros Garrison enters tapped.
When Boros Garrison enters, return a land you control to its owner's hand.
{T}: Add {R}{W}.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Candletrap

Enchant creature
Enchanted creature has defender.
Prevent all combat damage that would be dealt by enchanted creature.
Coven — {2}{W}, Sacrifice Candletrap: Exile enchanted creature. Activate only if you control three or more creatures with different powers.

Towering Viewpoint

Defender, reach
Leap of Faith — {3}: Target creature gains flying until end of turn.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Flamewright

{1}, {T}: Create a 1/1 colorless Construct artifact creature token with defender.
{T}, Sacrifice a creature with defender: Flamewright deals 1 damage to any target.

Wall of Frost

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

Sol Ring

Soulsworn Jury

Defender (This creature can't attack.)
{1}{U}, Sacrifice Soulsworn Jury: Counter target creature spell.

Walking Archive

Defender (This creature can't attack.)
Walking Archive enters with a +1/+1 counter on it.
At the beginning of each player's upkeep, that player draws a card for each +1/+1 counter on Walking Archive.
{2}{W}{U}: Put a +1/+1 counter on Walking Archive.

Mystic Gate

{T}: Add {C}.
{W/U}, {T}: Add {W}{W}, {W}{U}, or {U}{U}.

Corrupted Shapeshifter

Devoid (This card has no color.)
As Corrupted Shapeshifter enters, it becomes your choice of a 3/3 creature with flying, a 2/5 creature with vigilance, or a 0/12 creature with defender.

Wall of Water

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

Counterspell

Glacial Wall

Solar Blaze

Each creature deals damage to itself equal to its power.

Aetherflame Wall

Defender
Aetherflame Wall can block creatures with shadow as though they didn't have shadow.
{R}: Aetherflame Wall gets +1/+0 until end of turn.

Getting

Pramikon, Sky Rampart

Flying, defender
As Pramikon, Sky Rampart enters, choose left or right.
Each player may attack only the nearest opponent in the chosen direction and planeswalkers controlled by that opponent.

Wall of Air

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

Angelic Wall

Defender (This creature can't attack.)
Flying

Assassin Den

Defender (This creature can't attack.)
{3}{U}: Put a +1/+1 counter on target creature you control. It can't be blocked this turn. Activate only as a sorcery.

Secret Door

Defender
{4}{U}: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

High Alert

Each creature you control assigns combat damage equal to its toughness rather than its power.
Creatures you control can attack as though they didn't have defender.
{2}{W}{U}: Untap target creature.

Aurification

Whenever a creature deals damage to you, put a gold counter on it.
Each creature with a gold counter on it is a Wall in addition to its other creature types and has defender. (Those creatures can't attack.)
When Aurification leaves the battlefield, remove all gold counters from all creatures.

Wall of Granite

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Total War

Whenever a player attacks with one or more creatures, destroy all untapped non-Wall creatures that player controls that didn't attack, except for creatures the player hasn't controlled continuously since the beginning of the turn.

Mystic Monastery

Mystic Monastery enters tapped.
{T}: Add {U}, {R}, or {W}.

Hover Barrier

Boros Guildgate

This land enters tapped.
{T}: Add {R} or {W}.

Stalwart Shield-Bearers

Defender
Other creatures you control with defender get +0/+2.

Clockwork Drawbridge

Defender
{2}{W}, {T}: Tap target creature.

Wall of Essence

Defender (This creature can't attack.)
Whenever Wall of Essence is dealt combat damage, you gain that much life.

Wall of Heat

Resolute Watchdog

Defender
{1}, Sacrifice Resolute Watchdog: Target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Walking Bulwark

Defender
{2}: Until end of turn, target creature with defender gains haste, can attack as though it didn't have defender, and assigns combat damage equal to its toughness rather than its power. Activate only as a sorcery.

Flumph

Defender, flying
Whenever Flumph is dealt damage, you and target opponent each draw a card.

Rugged Prairie

{T}: Add {C}.
{R/W}, {T}: Add {R}{R}, {R}{W}, or {W}{W}.

Murmuring Phantasm

Shield-Wall Sentinel

Defender
When Shield-Wall Sentinel enters, you may search your library for a creature card with defender, reveal it, put it into your hand, then shuffle.

Time Wipe

Return a creature you control to its owner's hand, then destroy all creatures.

Bonded Fetch

Defender, haste
{T}: Draw a card, then discard a card.

Rammas Echor, Ancient Shield

Whenever you cast your second spell each turn, draw a card, then create a 0/3 white Wall creature token with defender.
At the beginning of combat on your turn, creatures you control with defender gain exalted until end of turn. (Whenever a creature you control attacks alone, it gets +1/+1 until end of turn for each instance of exalted among permanents you control.)

Wall of Stone

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Teyo, Geometric Tactician

When Teyo, Geometric Tactician enters, create a 0/4 white Wall creature token with defender and flying.
+1: You and target opponent each draw a card.
−2: Choose left or right. Until your next turn, each player may attack only the nearest opponent in the last chosen direction and planeswalkers controlled by that opponent.

Perimeter Captain

Defender
Whenever a creature you control with defender blocks, you may gain 2 life.

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.

Azorius Guildgate

This land enters tapped.
{T}: Add {W} or {U}.

Aether Membrane

Defender; reach (This creature can block creatures with flying.)
Whenever Aether Membrane blocks a creature, return that creature to its owner's hand at end of combat.

Command Tower

Vent Sentinel

Defender
{1}{R}, {T}: Vent Sentinel deals damage to target player or planeswalker equal to the number of creatures you control with defender.

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Wall of Earth

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Nesting Dragon

Flying
Landfall — Whenever a land you control enters, create a 0/2 red Dragon Egg creature token with defender and "When this creature dies, create a 2/2 red Dragon creature token with flying and '{R}: This creature gets +1/+0 until end of turn.'"

Amaranthine Wall

Defender
{2}: Amaranthine Wall gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Riptide Turtle

Fortified Rampart

Island

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.

Slagwurm Armor

Equipped creature gets +0/+6.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Walking Wall

Defender
{3}: Walking Wall gets +3/-1 until end of turn and can attack this turn as though it didn't have defender. Activate only once each turn.

Quicksilver Wall

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

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Wall of Denial

Defender, flying
Shroud (This creature can't be the target of spells or abilities.)

Wall of Omens

Defender
When Wall of Omens enters, draw a card.

Wall of Resistance

Defender (This creature can't attack.)
Flying
At the beginning of each end step, if Wall of Resistance was dealt damage this turn, put a +0/+1 counter on it.

Weathered Sentinels

Defender, vigilance, reach, trample
Weathered Sentinels can attack players who attacked you during their last turn as though it didn't have defender.
Whenever Weathered Sentinels attacks, it gets +3/+3 and gains indestructible until end of turn.

Guardians of Meletis

Monastery Flock

Defender, flying
Morph {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.)

Coral Colony

Defender
{1}{U}, {T}: Target player mills X cards, where X is the number of creatures you control with defender. (To mill a card, a player puts the top card of their library into their graveyard.)

Wall of Diffusion

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

Fog Bank

Defender (This creature can't attack.)
Flying
Prevent all combat damage that would be dealt to and dealt by this creature.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Stoneskin

Flash
Enchant creature
Enchanted creature gets +0/+10.

Plains

Cascade Bluffs

{T}: Add {C}.
{U/R}, {T}: Add {U}{U}, {U}{R}, or {R}{R}.

Mountain

Skycloud Expanse

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Master Warcraft

Cast this spell only before attackers are declared.
You choose which creatures attack this turn.
You choose which creatures block this turn and how those creatures block.