The Pride of Hull Clade

This spell costs {X} less to cast, where X is the total toughness of creatures you control.
Defender
{2}{U}{U}: Until end of turn, target creature you control gets +1/+0, gains "Whenever this creature deals combat damage to a player, draw cards equal to its toughness," and can attack as though it didn't have defender.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

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.

Jeskai Barricade

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

Command Tower

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

Crashing Drawbridge

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

Vine Trellis

Defender (This creature can't attack.)
{T}: Add {G}.

Canopy Vista

({T}: Add {G} or {W}.)
This land enters tapped unless you control two or more basic lands.

Assault Formation

Each creature you control assigns combat damage equal to its toughness rather than its power.
{G}: Target creature with defender can attack this turn as though it didn't have defender.
{2}{G}: Creatures you control get +0/+1 until end of turn.

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.)

Shield-Wall Sentinel

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

Fell the Mighty

Destroy all creatures with power greater than target creature's power.

Wall of Stolen Identity

You may have this creature 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 this creature.

Arcades, the Strategist

Flying, vigilance
Whenever a creature you control with defender enters, draw a card.
Each creature you control with defender assigns combat damage equal to its toughness rather than its power and can attack as though it didn't have defender.

Wall of Denial

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

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Wall of Omens

Defender
When this creature enters, draw a card.

Arcane Signet

Axebane Guardian

Defender
{T}: Add X mana in any combination of colors, where X is the number of creatures you control with defender.

Sunscape Familiar

Defender (This creature can't attack.)
Green spells and blue spells you cast cost {1} less to cast.

Seaside Citadel

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

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Overgrown Battlement

Defender
{T}: Add {G} for each creature you control with defender.

Sylvan Caryatid

Defender, hexproof
{T}: Add one mana of any color.

Wall of Blossoms

Stalwart Shield-Bearers

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

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.