Tarnished Citadel

{T}: Add {C}.
{T}: Add one mana of any color. This land deals 3 damage to you.

Scout's Warning

The next creature card you play this turn can be played as though it had flash.
Draw a card.

Treetop Village

This land enters tapped.
{T}: Add {G}.
{1}{G}: This land becomes a 3/3 green Ape creature with trample until end of turn. It's still a land. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Valakut, the Molten Pinnacle

This land enters tapped.
Whenever a Mountain you control enters, if you control at least five other Mountains, you may have this land deal 3 damage to any target.
{T}: Add {R}.

Appa, the Vigilant

Flying, vigilance
Whenever Appa or another Ally you control enters, creatures you control get +1/+1 and gain flying and vigilance until end of turn.

Katara's Reversal

Counter up to four target spells and/or abilities.
Untap up to four target artifacts and/or creatures.

Fire Nation Turret

At the beginning of combat on your turn, up to one target creature gets +2/+0 and gains firebending 2 until end of turn.
{R}: Put a charge counter on this artifact.
Remove fifty charge counters from this artifact: It deals 50 damage to any target.

Swampbenders

Swampbenders's power and toughness are each equal to the number of Swamps on the battlefield.
Lands you control are Swamps in addition to their other types.

Sokka's Charge

During your turn, Allies you control have double strike and lifelink.

Earthshape

Earthbend 3. Then each creature you control with power less than or equal to that land's power gains hexproof and indestructible until end of turn. You gain hexproof until end of turn.

Mai and Zuko

Firebending 3
You may cast Ally spells and artifact spells as though they had flash.

Aang and Katara

Ally

Whenever Aang and Katara enter or attack, create X 1/1 white Ally creature tokens, where X is the number of tapped artifacts and/or creatures you control.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Toph, Greatest Earthbender

When Toph enters, earthbend X, where X is the amount of mana spent to cast her.
Land creatures you control have double strike.

Sokka and Suki

Whenever Sokka and Suki or another Ally you control enters, attach up to one target Equipment you control to that creature.
Whenever an Equipment you control enters, create a 1/1 white Ally creature token.

Momo's Heist

Gain control of target artifact. Untap it. It gains haste. At the beginning of the next end step, sacrifice it.

Avatar: The Last Airbender Eternal