Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Arcane Signet

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

Slinn Voda, the Rising Deep

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
When Slinn Voda, the Rising Deep enters the battlefield, if it was kicked, return all creatures to their owners' hands except for Merfolk, Krakens, Leviathans, Octopuses, and Serpents.

Octoprophet

When Octoprophet enters the battlefield, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Kenessos, Priest of Thassa

If you would scry a number of cards, scry that many cards plus one instead.
{3}{G/U}: Look at the top card of your library. If it's a Kraken, Leviathan, Octopus, or Serpent creature card, you may put it onto the battlefield. If you don't put the card onto the battlefield, you may put it on the bottom of your library.

Koma, Cosmos Serpent

This spell can't be countered.
At the beginning of each upkeep, create a 3/3 blue Serpent creature token named Koma's Coil.
Sacrifice another Serpent: Choose one —
• Tap target permanent. Its activated abilities can't be activated this turn.
• Koma, Cosmos Serpent gains indestructible until end of turn.

Timeless Witness

When Timeless Witness enters the battlefield, return target card from your graveyard to your hand.
Eternalize {5}{G}{G} ({5}{G}{G}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Human Shaman with no mana cost. Eternalize only as a sorcery.)

Tromokratis

Tromokratis has hexproof unless it's attacking or blocking.
Tromokratis can't be blocked unless all creatures defending player controls block it. (If any creature that player controls doesn't block this creature, it can't be blocked.)

Command Tower

Rishkar's Expertise

Draw cards equal to the greatest power among creatures you control.
You may cast a spell with mana value 5 or less from your hand without paying its mana cost.

Serpent of Yawning Depths

Krakens, Leviathans, Octopuses, and Serpents you control can't be blocked except by Krakens, Leviathans, Octopuses, and Serpents.

Tidechannel Pathway

Barkchannel Pathway

Barkchannel Pathway // Tidechannel Pathway

Explore

You may play an additional land this turn.
Draw a card.

Snow-Covered Island

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Biomancer's Familiar

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.
{T}: The next time target creature adapts this turn, it adapts as though it had no +1/+1 counters on it.

Birds of Paradise

Brinelin, the Moon Kraken

When Brinelin, the Moon Kraken enters the battlefield or whenever you cast a spell with mana value 6 or greater, you may return target nonland permanent to its owner's hand.
Partner (You can have two commanders if both have partner.)

Kiora, Sovereign of the Deep

Vigilance, ward {3}
Whenever you cast a Kraken, Leviathan, Octopus, or Serpent spell from your hand, look at the top X cards of your library, where X is that spell's mana value. You may cast a spell with mana value less than X from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

Omen Hawker

{T}: Add {C}{U}. Spend this mana only to activate abilities.

Counterspell

Elemental Bond

Whenever a creature with power 3 or greater enters the battlefield under your control, draw a card.

Scourge of Fleets

When Scourge of Fleets enters the battlefield, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.

Dreamroot Cascade

Dreamroot Cascade enters the battlefield tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

Arixmethes, Slumbering Isle

Arixmethes, Slumbering Isle enters the battlefield tapped with five slumber counters on it.
As long as Arixmethes has a slumber counter on it, it's a land. (It's not a creature.)
Whenever you cast a spell, you may remove a slumber counter from Arixmethes.
{T}: Add {G}{U}.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Temple of Mystery

Temple of Mystery enters the battlefield tapped.
When Temple of Mystery enters the battlefield, scry 1.
{T}: Add {G} or {U}.

Sol Ring

Trench Behemoth

Return a land you control to its owner's hand: Untap Trench Behemoth. It gains hexproof until end of turn.
Landfall — Whenever a land enters the battlefield under your control, target creature an opponent controls attacks during its controller's next combat phase if able.

Quandrix Campus

Quandrix Campus enters the battlefield tapped.
{T}: Add {G} or {U}.
{4}, {T}: Scry 1.

Eternal Witness

When Eternal Witness enters the battlefield, you may return target card from your graveyard to your hand.

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. Yavimaya Coast deals 1 damage to you.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Xolatoyac, the Smiling Flood

Whenever Xolatoyac, the Smiling Flood enters the battlefield or attacks, put a flood counter on target land. That land is an Island in addition to its other types for as long as it has a flood counter on it.
At the beginning of your end step, untap each permanent you control with a counter on it.

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.

Scroll Rack

{1}, {T}: Exile any number of cards from your hand face down. Put that many cards from the top of your library into your hand. Then look at the exiled cards and put them on top of your library in any order.

Ram Through

Target creature you control deals damage equal to its power to target creature you don't control. If the creature you control has trample, excess damage is dealt to that creature's controller instead.

Octavia, Living Thesis

This spell costs {8} less to cast if you have eight or more instant and/or sorcery cards in your graveyard.
Ward {8}
Magecraft — Whenever you cast or copy an instant or sorcery spell, target creature has base power and toughness 8/8 until end of turn.

Rimewood Falls

({T}: Add {G} or {U}.)
Rimewood Falls enters the battlefield tapped.

Simic Sky Swallower

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

Kodama's Reach

Snow-Covered Forest

Icebreaker Kraken

This spell costs {1} less to cast for each snow land you control.
When Icebreaker Kraken enters the battlefield, artifacts and creatures target opponent controls don't untap during that player's next untap step.
Return three snow lands you control to their owner's hand: Return Icebreaker Kraken to its owner's hand.

Halimar Depths

Halimar Depths enters the battlefield tapped.
When Halimar Depths enters the battlefield, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

Spawning Kraken

Whenever a Kraken, Leviathan, Octopus, or Serpent you control deals combat damage to a player, create a 9/9 blue Kraken creature token.

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.

Uro, Titan of Nature's Wrath

When Uro enters the battlefield, sacrifice it unless it escaped.
Whenever Uro enters the battlefield or attacks, you gain 3 life and draw a card, then you may put a land card from your hand onto the battlefield.
Escape—{G}{G}{U}{U}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Stormtide Leviathan

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
All lands are Islands in addition to their other types.
Creatures without flying or islandwalk can't attack.

Lifecrafter's Bestiary

At the beginning of your upkeep, scry 1.
Whenever you cast a creature spell, you may pay {G}. If you do, draw a card.

Alchemist's Refuge

{T}: Add {C}.
{G}{U}, {T}: You may cast spells this turn as though they had flash.

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Farseek

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

Biblioplex Kraken

When Biblioplex Kraken enters the battlefield, scry 3. (Look at the top three cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)
Whenever Biblioplex Kraken attacks, you may return another creature you control to its owner's hand. If you do, Biblioplex Kraken can't be blocked this turn.

Wilderness Reclamation

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

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Kinnan, Bonder Prodigy

Whenever you tap a nonland permanent for mana, add one mana of any type that permanent produced.
{5}{G}{U}: Look at the top five cards of your library. You may put a non-Human creature card from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Vineglimmer Snarl

As Vineglimmer Snarl enters the battlefield, you may reveal a Forest or Island card from your hand. If you don't, Vineglimmer Snarl enters the battlefield tapped.
{T}: Add {G} or {U}.

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Flooded Grove

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

Rejuvenating Springs

Rejuvenating Springs enters the battlefield tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Whelming Wave

Return all creatures to their owners' hands except for Krakens, Leviathans, Octopuses, and Serpents.

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Sylvan Library

At the beginning of your draw step, you may draw two additional cards. If you do, choose two cards in your hand drawn this turn. For each of those cards, pay 4 life or put the card on top of your library.

Seedborn Muse

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

Thassa, God of the Sea

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
At the beginning of your upkeep, scry 1.
{1}{U}: Target creature you control can't be blocked this turn.

Kiora, Behemoth Beckoner

Whenever a creature with power 4 or greater enters the battlefield under your control, draw a card.
−1: Untap target permanent.

Hinterland Harbor

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Aesi, Tyrant of Gyre Strait

You may play an additional land on each of your turns.
Landfall — Whenever a land enters the battlefield under your control, you may draw a card.

Zhalfirin Void

When Zhalfirin Void enters the battlefield, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)
{T}: Add {C}.

Castle Vantress

Castle Vantress enters the battlefield tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

Garruk's Uprising

When Garruk's Uprising enters the battlefield, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample. (They can deal excess combat damage to the player or planeswalker they're attacking.)
Whenever a creature with power 4 or greater enters the battlefield under your control, draw a card.

Lorthos, the Tidemaker

Whenever Lorthos, the Tidemaker attacks, you may pay {8}. If you do, tap up to eight target permanents. Those permanents don't untap during their controllers' next untap steps.

Harmonize

Joint Exploration

Kicker {G} (You may pay an additional {G} as you cast this spell.)
Scry 2, then draw a card. If this spell was kicked, you may put a land card from your hand onto the battlefield.

Crystal Ball

{1}, {T}: Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Inkwell Leviathan

Trample
Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Shroud (This creature can't be the target of spells or abilities.)

Quest for Ula's Temple

At the beginning of your upkeep, you may look at the top card of your library. If it's a creature card, you may reveal it and put a quest counter on Quest for Ula's Temple.
At the beginning of each end step, if there are three or more quest counters on Quest for Ula's Temple, you may put a Kraken, Leviathan, Octopus, or Serpent creature card from your hand onto the battlefield.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Kederekt Leviathan

When Kederekt Leviathan enters the battlefield, return all other nonland permanents to their owners' hands.
Unearth {6}{U} ({6}{U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Pearl Lake Ancient

Flash
This spell can't be countered.
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Return three lands you control to their owner's hand: Return Pearl Lake Ancient to its owner's hand.