Secret of Bloodbending

As an additional cost to cast this spell, you may waterbend {10}.
You control target opponent during their next combat phase. If this spell's additional cost was paid, you control that player during their next turn instead. (You see all cards that player could see and make all decisions for them.)
Exile Secret of Bloodbending.

Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

We Ride at Dawn

Legendary creature spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a legendary creature spell pays for {1} or one mana of that creature's color.)
Whenever your commander attacks, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."

Arbiter of the Ideal

Flying
Inspired — Whenever this creature becomes untapped, reveal the top card of your library. If it's an artifact, creature, or land card, you may put it onto the battlefield with a manifestation counter on it. That permanent is an enchantment in addition to its other types.

Monologue Tax

Whenever an opponent casts their second spell each turn, you create a Treasure token.

White Plume Adventurer

When this creature enters, you take the initiative.
At the beginning of each opponent's upkeep, untap a creature you control. If you've completed a dungeon, untap all creatures you control instead.

Clever Concealment

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Any number of target nonland permanents you control phase out. (Treat them and anything attached to them as though they don't exist until your next turn.)

Benevolent River Spirit

As an additional cost to cast this spell, waterbend {5}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
Flying, ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
When this creature enters, scry 2.

Interface Ace

This creature saddles Mounts and crews Vehicles using its toughness rather than its power.
Whenever this creature becomes tapped during your turn, untap it. This ability triggers only once each turn.

Unstoppable Plan

At the beginning of your end step, untap all nonland permanents you control.

Daring Thief

Inspired — Whenever this creature 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.

Brave the Sands

Creatures you control have vigilance.
Each creature you control can block an additional creature each combat.

Beza, the Bounding Spring

When Beza enters, create a Treasure token if an opponent controls more lands than you. You gain 4 life if an opponent has more life than you. Create two 1/1 blue Fish creature tokens if an opponent controls more creatures than you. Draw a card if an opponent has more cards in hand than you.

Stonybrook Schoolmaster

Whenever this creature becomes tapped, you may create a 1/1 blue Merfolk Wizard creature token.

Lulu, Loyal Hollyphant

Flying
At the beginning of your end step, if a permanent you controlled left the battlefield this turn, put a +1/+1 counter on each tapped creature you control, then untap them.
Choose a Background (You can have a Background as a second commander.)

Aang and La, Ocean's Fury

Reach, trample
Whenever Aang and La attack, put a +1/+1 counter on each tapped creature you control.

Aang, Swift Savior

Flash
Flying
When Aang enters, airbend up to one other target creature or spell. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)
Waterbend {8}: Transform Aang.

Aang, Swift Savior // Aang and La, Ocean's Fury

Compassionate Healer

Whenever this creature becomes tapped, you gain 1 life and scry 1. (Look at the top card of your library. You may put it on the bottom.)

Veteran Survivor

Survival — At the beginning of your second main phase, if this creature is tapped, exile up to one target card from a graveyard.
As long as there are three or more cards exiled with this creature, it gets +3/+3 and has hexproof. (It can't be the target of spells or abilities your opponents control.)

Katara, Bending Prodigy

At the beginning of your end step, if Katara is tapped, put a +1/+1 counter on her.
Waterbend {6}: Draw a card. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

Devouring Light

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Exile target attacking or blocking creature.

Spider-UK

Web-slinging {2}{W} (You may cast this spell for {2}{W} if you also return a tapped creature you control to its owner's hand.)
At the beginning of your end step, if two or more creatures entered the battlefield under your control this turn, you draw a card and gain 2 life.

Azorius Signet

Spider-Sense

Web-slinging {U} (You may cast this spell for {U} if you also return a tapped creature you control to its owner's hand.)
Counter target instant spell, sorcery spell, or triggered ability.

Temple of Enlightenment

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {W} or {U}.

Avatar Kuruk

Whenever you cast a spell, create a 1/1 colorless Spirit creature token with "This token can't block or be blocked by non-Spirit creatures."
Exhaust — Waterbend {20}: Take an extra turn after this one. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}. Activate each exhaust ability only once.)

The Legend of Kuruk

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Scry 2, then draw a card.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Legend of Kuruk // Avatar Kuruk

Tui and La, Moon and Ocean

Whenever Tui and La become tapped, draw a card.
Whenever Tui and La become untapped, put a +1/+1 counter on them.

Split Up

Choose one —
• Destroy all tapped creatures.
• Destroy all untapped creatures.

Gran-Gran

Whenever Gran-Gran becomes tapped, draw a card, then discard a card.
Noncreature spells you cast cost {1} less to cast as long as there are three or more Lesson cards in your graveyard.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Sky Hussar

Flying
When this creature enters, untap all creatures you control.
Forecast — Tap two untapped white and/or blue creatures you control, Reveal this card from your hand: Draw a card. (Activate only during your upkeep and only once each turn.)

Ephemeral Shields

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Lost in the Maze

Flash
When this enchantment enters, tap X target creatures. Put a stun counter on each of those creatures you don't control. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Tapped creatures you control have hexproof.

Drumbellower

Flying
Untap all creatures you control during each other player's untap step.

Spell Swindle

Counter target spell. Create X Treasure tokens, where X is that spell's mana value. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Arcane Signet

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

Floodfarm Verge

{T}: Add {W}.
{T}: Add {U}. Activate only if you control a Plains or an Island.

Prop Room

Untap each creature you control during each other player's untap step.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Dazzling Theater

Creature spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a creature spell pays for {1} or one mana of that creature's color.)
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Dazzling Theater // Prop Room

Deserted Beach

This land enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Sol Ring

Attentive Sunscribe

Whenever this creature becomes tapped, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

The Unagi of Kyoshi Island

Flash
Ward—Waterbend {4} (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
Whenever an opponent draws their second card each turn, draw two cards.

Sea of Clouds

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Aang's Iceberg

Flash
When this enchantment enters, exile up to one other target nonland permanent until this enchantment leaves the battlefield.
Waterbend {3}: Sacrifice this enchantment. If you do, scry 2. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

Everything Comes to Dust

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Exile all creatures except those that share a creature type with a creature that convoked this spell, all artifacts, and all enchantments.

Nimbus Maze

{T}: Add {C}.
{T}: Add {W}. Activate only if you control an Island.
{T}: Add {U}. Activate only if you control a Plains.

Yue, the Moon Spirit

Flying, vigilance
Waterbend {5}, {T}: You may cast a noncreature spell from your hand without paying its mana cost.

Howling Mine

At the beginning of each player's draw step, if this artifact is untapped, that player draws an additional card.

Unswerving Sloth

Whenever this creature attacks while saddled, it gains indestructible until end of turn. Untap all creatures you control.
Saddle 4 (Tap any number of other creatures you control with total power 4 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Water Whip

As an additional cost to cast this spell, waterbend {5}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
Return up to two target creatures to their owners' hands. Draw two cards.

White Sun's Twilight

You gain X life. Create X 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This token can't block." If X is 5 or more, destroy all other creatures. (Players dealt combat damage by a creature with toxic 1 also get a poison counter.)

Artistic Refusal

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Choose one or both —
• Counter target spell.
• Draw two cards, then discard a card.

Master of Ceremonies

At the beginning of your upkeep, each opponent chooses money, friends, or secrets. For each player who chose money, you and that player each create a Treasure token. For each player who chose friends, you and that player each create a 1/1 green and white Citizen creature token. For each player who chose secrets, you and that player each draw a card.

Spirit Water Revival

As an additional cost to cast this spell, you may waterbend {6}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
Draw two cards. If this spell's additional cost was paid, instead shuffle your graveyard into your library, draw seven cards, and you have no maximum hand size for the rest of the game.
Exile Spirit Water Revival.

Sunstrike Legionnaire

This creature doesn't untap during your untap step.
Whenever another creature enters, untap this creature.
{T}: Tap target creature with mana value 3 or less.

Mistmeadow Vanisher

Whenever this creature becomes tapped, exile up to one target nonland, nontoken permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Arachne, Psionic Weaver

Web-slinging {W} (You may cast this spell for {W} if you also return a tapped creature you control to its owner's hand.)
As Arachne enters, look at an opponent's hand, then choose a card type other than creature.
Spells of the chosen type cost {1} more to cast.

Wand of the Worldsoul

This artifact enters tapped.
{T}: Add {W}.
{T}: The next spell you cast this turn has convoke.

Fellwar Stone

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

Mystic Gate

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

Plains

Island

Gideon, Martial Paragon

+2: Untap all creatures you control. Those creatures get +1/+1 until end of turn.
0: Until end of turn, Gideon becomes a 5/5 Human Soldier creature with indestructible that's still a planeswalker. Prevent all damage that would be dealt to him this turn.
−10: Creatures you control get +2/+2 until end of turn. Tap all creatures your opponents control.

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. This land deals 1 damage to you.

Rent Is Due

At the beginning of your end step, you may tap two untapped creatures and/or Treasures you control. If you do, draw a card. Otherwise, sacrifice this enchantment.

Watery Grasp

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
Waterbend {5}: Enchanted creature's owner shuffles it into their library. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)

Elspeth, Storm Slayer

If one or more tokens would be created under your control, twice that many of those tokens are created instead.
+1: Create a 1/1 white Soldier creature token.
0: Put a +1/+1 counter on each creature you control. Those creatures gain flying until your next turn.
−3: Destroy target creature an opponent controls with mana value 3 or greater.

Entrapment Maneuver

Target player sacrifices an attacking creature of their choice. You create X 1/1 white Soldier creature tokens, where X is that creature's toughness.

Interdisciplinary Mascot

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Ward {3}
When this creature enters, look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in a random order.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. This artifact deals 1 damage to you.

Port Town

As this land enters, you may reveal a Plains or Island card from your hand. If you don't, this land enters tapped.
{T}: Add {W} or {U}.

Genesis Chamber

Whenever a nontoken creature enters, if this artifact is untapped, that creature's controller creates a 1/1 colorless Myr artifact creature token.

Ardenvale Fealty

Create a 2/2 white Knight creature token with vigilance. (Then exile this card. You may cast the enchantment later from exile.)

Virtue of Loyalty

At the beginning of your end step, put a +1/+1 counter on each creature you control. Untap those creatures.

Virtue of Loyalty // Ardenvale Fealty

Savior of the Small

Survival — At the beginning of your second main phase, if this creature is tapped, return target creature card with mana value 3 or less from your graveyard to your hand.

Glacial Fortress

This land enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Bennie Bracks, Zoologist

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
At the beginning of each end step, if you created a token this turn, draw a card.

Mechan Navigator

Whenever this creature becomes tapped, draw a card, then discard a card.

Caetus, Sea Tyrant of Segovia

Noncreature spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a noncreature spell pays for {1} or one mana of that creature's color.)
At the beginning of your end step, untap up to four target creatures.

Invasion of Segovia

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, create two 1/1 blue Kraken creature tokens with trample.

Invasion of Segovia // Caetus, Sea Tyrant of Segovia

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Exotic Orchard

Immovable Rod

You may choose not to untap this artifact during your untap step.
Whenever this artifact becomes untapped, venture into the dungeon.
{3}{W}, {T}: For as long as this artifact remains tapped, another target permanent loses all abilities and can't attack or block.

Prairie Stream

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

Zephyr Singer

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Flying, vigilance
When this creature enters, put a flying counter on each creature that convoked it.

Skycloud Expanse

Flockchaser Phantom

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Flying, vigilance
Whenever this creature attacks, the next spell you cast this turn has convoke.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Chant of Vitu-Ghazi

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Prevent all damage that would be dealt by creatures this turn. You gain life equal to the damage prevented this way.

Command Tower

Starfighter Pilot

Whenever this creature becomes tapped, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

The Wandering Rescuer

Flash
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Double strike
Other tapped creatures you control have hexproof.

Glimmer Seeker

Survival — At the beginning of your second main phase, if this creature is tapped, draw a card if you control a Glimmer creature. If you don't control a Glimmer creature, create a 1/1 white Glimmer enchantment creature token.

Throne of the God-Pharaoh

At the beginning of your end step, each opponent loses life equal to the number of tapped creatures you control.

Knight-Errant of Eos

Convoke
When this creature enters, look at the top six cards of your library. You may reveal up to two creature cards with mana value X or less from among them, where X is the number of creatures that convoked this creature. Put the revealed cards into your hand, then shuffle.

Conclave Tribunal

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
When this enchantment enters, exile target nonland permanent an opponent controls until this enchantment leaves the battlefield.

Water Tribe Rallier

Waterbend {5}: Look at the top four cards of your library. You may reveal a creature card with power 3 or less from among them and put it into your hand. Put the rest on the bottom of your library in a random order. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)