Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Negate

Aegis Turtle

Command Tower

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

Arcane Signet

Mentor of the Meek

Whenever another creature you control with power 2 or less enters, you may pay {1}. If you do, draw a card.

Plains

Scavenger Grounds

{T}: Add {C}.
{2}, {T}, Sacrifice a Desert: Exile all graveyards.

Reliquary Tower

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

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Prairie Stream

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

Counterspell

Fellwar Stone

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

Expel the Interlopers

Choose a number between 0 and 10. Destroy all creatures with power greater than or equal to the chosen number.

Teferi's Time Twist

Exile target permanent you control. Return that card to the battlefield under its owner's control at the beginning of the next end step. If it enters as a creature, it enters with an additional +1/+1 counter on it.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Kraken Hatchling

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.

Azorius Signet

Long River's Pull

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Counter target creature spell. If the gift was promised, instead counter target spell.

Venture Deeper

Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)

Merfolk Secretkeeper

Merfolk Secretkeeper // Venture Deeper

Brago, King Eternal

Flying
Whenever Brago, King Eternal deals combat damage to a player, exile any number of target nonland permanents you control, then return those cards to the battlefield under their owner's control.

Assemble the Players

You may look at the top card of your library any time.
Once each turn, you may cast a creature spell with power 2 or less from the top of your library.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

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.

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."

Disenchant

Thought Vessel

Shore Keeper

{7}{U}, {T}, Sacrifice Shore Keeper: Draw three cards.

Adarkar Wastes

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

Requisition Raid

Spree (Choose one or more additional costs.)
+ {1} — Destroy target artifact.
+ {1} — Destroy target enchantment.
+ {1} — Put a +1/+1 counter on each creature target player controls.

Glistener Seer

Glistener Seer enters with three oil counters on it.
{T}, Remove an oil counter from Glistener Seer: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Dawn

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Return all creature cards with power 2 or less from your graveyard to your hand.

Dusk

Destroy all creatures with power 3 or greater.

Dusk // Dawn

Access Tunnel

{T}: Add {C}.
{3}, {T}: Target creature with power 3 or less can't be blocked this turn.

Ornithopter

Shorecomber Crab

Island

Swords to Plowshares

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

Plagon, Lord of the Beach

When Plagon, Lord of the Beach enters, draw a card for each creature you control with toughness greater than its power.
{W/U}: Target creature you control assigns combat damage equal to its toughness rather than its power this turn.

Gossip's Talent

(Gain the next level as a sorcery to add its ability.)
Whenever a creature you control enters, surveil 1.
{1}{U}: Level 2
Whenever you attack, target attacking creature with power 3 or less can't be blocked this turn.
{3}{U}: Level 3
Whenever a creature you control deals combat damage to a player, you may exile it, then return it to the battlefield under its owner's control.

Felidar Guardian

When Felidar Guardian enters, you may exile another target permanent you control, then return that card to the battlefield under its owner's control.

Planar Incision

Exile target artifact or creature, then return it to the battlefield under its owner's control with a +1/+1 counter on it.

Yoked Ox

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

The Council of Four

Whenever a player draws their second card during their turn, you draw a card.
Whenever a player casts their second spell during their turn, you create a 2/2 white Knight creature token.

Aven Envoy

Raise the Past

Return all creature cards with mana value 2 or less from your graveyard to the battlefield.

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Valiant Guard

Angelic Shield

Creatures you control get +0/+1.
Sacrifice Angelic Shield: Return target creature to its owner's hand.

Dromoka Dunecaster

{1}{W}, {T}: Tap target creature without flying.

Restoration Angel

Flash
Flying
When Restoration Angel enters, you may exile target non-Angel creature you control, then return that card to the battlefield under your control.

Glacial Fortress

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

Cloudfin Raptor

Flying
Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)

Armored Armadillo

Ward {1} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
{3}{W}: Armored Armadillo gets +X/+0 until end of turn, where X is its toughness.

Thriving Turtle

When Thriving Turtle enters, you get {E}{E} (two energy counters).
Whenever Thriving Turtle attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. Talisman of Progress deals 1 damage to you.

Port Town

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

Skycloud Expanse

Elite Arrester

Baldin, Century Herdmaster

As long as it's your turn, each creature assigns combat damage equal to its toughness rather than its power.
Whenever Baldin, Century Herdmaster attacks, up to one hundred target creatures each get +0/+X until end of turn, where X is the number of cards in your hand.

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.

Sea Gate Oracle

When Sea Gate Oracle enters, look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Rasaad yn Bashir

Each creature you control assigns combat damage equal to its toughness rather than its power.
Whenever Rasaad yn Bashir attacks, if you have the initiative, double the toughness of each creature you control until end of turn.
Choose a Background (You can have a Background as a second commander.)

Charix, the Raging Isle

Spells your opponents cast that target Charix, the Raging Isle cost {2} more to cast.
{3}: Charix gets +X/-X until end of turn, where X is the number of Islands you control.

Tasseled Dromedary

Parting Gust

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Exile target nontoken creature. If the gift wasn't promised, return that card to the battlefield under its owner's control with a +1/+1 counter on it at the beginning of the next end step.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Sol Ring

Azorius Chancery

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

Inquisitive Puppet

When Inquisitive Puppet enters, scry 1.
Exile Inquisitive Puppet: Create a 1/1 white Human creature token.

Phyrexian Walker

Serra Redeemer

Flying
Whenever another creature you control with power 2 or less enters, put two +1/+1 counters on that creature.

Gauntlets of Light

Enchant creature
Enchanted creature gets +0/+2 and assigns combat damage equal to its toughness rather than its power.
Enchanted creature has "{2}{W}: Untap this creature."

Slaughter the Strong

Each player chooses any number of creatures they control with total power 4 or less, then sacrifices all other creatures they control.