Shape the Sands

Target creature gets +0/+5 and gains reach until end of turn. (It can block creatures with flying.)

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with this creature's toughness.

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.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Doran, the Siege Tower

Each creature assigns combat damage equal to its toughness rather than its power.

Felothar the Steadfast

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.
{3}, {T}, Sacrifice another creature: Draw cards equal to the sacrificed creature's toughness, then discard cards equal to its power.

Tree of Redemption

Defender
{T}: Exchange your life total with this creature's toughness.

Tower Defense

Creatures you control get +0/+5 and gain reach until end of turn.

Ikra Shidiqi, the Usurper

Menace
Whenever a creature you control deals combat damage to a player, you gain life equal to that creature's toughness.
Partner (You can have two commanders if both have partner.)

The Walls of Ba Sing Se

Defender
Other permanents you control have indestructible.

Wall of Shards

Defender, flying
Cumulative upkeep—An opponent gains 1 life. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)