Elder Deep-Fiend

Flash
Emerge {5}{U}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, tap up to four target permanents.

Unwind

Counter target noncreature spell. Untap up to three lands.

Finale of Revelation

Draw X cards. If X is 10 or more, instead shuffle your graveyard into your library, draw X cards, untap up to five lands, and you have no maximum hand size for the rest of the game.
Exile Finale of Revelation.

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.

Forest

Monstrous Vortex

Whenever you cast a creature spell with power 5 or greater, discover X, where X is that spell's mana value. (Exile cards from the top of your library until you exile a nonland card with that mana value or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Reservoir Kraken

Trample, ward {2}
At the beginning of each combat, if Reservoir Kraken is untapped, any opponent may tap an untapped creature they control. If they do, tap Reservoir Kraken and create a 1/1 blue Fish creature token with "This creature can't be blocked."

Llanowar Elves

Talisman of Curiosity

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

Emergent Woodwurm

Backup 3 (When this creature enters the battlefield, put three +1/+1 counters on target creature. If that's another creature, it gains the following ability until end of turn.)
Whenever this creature attacks, look at the top X cards of your library, where X is its power. You may put a permanent card with mana value X or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

Prime Speaker Zegana

Prime Speaker Zegana enters the battlefield with X +1/+1 counters on it, where X is the greatest power among other creatures you control.
When Prime Speaker Zegana enters the battlefield, draw cards equal to its power.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Coiling Oracle

When Coiling Oracle enters the battlefield, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

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.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Quicksilver Amulet

{4}, {T}: You may put a creature card from your hand onto the battlefield.

Simic Signet

Devastation Tide

Return all nonland permanents to their owners' hands.
Miracle {1}{U} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

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.

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.

Monstrosity of the Lake

When Monstrosity of the Lake enters the battlefield, you may pay {5}. If you do, tap all creatures your opponents control, then put a stun counter on each of those creatures. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Islandcycling {2} ({2}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Nadir Kraken

Whenever you draw a card, you may pay {1}. If you do, put a +1/+1 counter on Nadir Kraken and create a 1/1 blue Tentacle creature token.

Gyre Engineer

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.)

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.

Kraken of the Straits

Creatures with power less than the number of Islands you control can't block Kraken of the Straits.

Shipbreaker Kraken

{6}{U}{U}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.)
When Shipbreaker Kraken becomes monstrous, tap up to four target creatures. Those creatures don't untap during their controllers' untap steps for as long as you control Shipbreaker Kraken.

Make Your Own Luck

Look at the top three cards of your library. You may exile a nonland card from among them. If you do, it becomes plotted. Put the rest into your hand. (You may cast it as a sorcery on a later turn without paying its mana cost.)

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}.

Whelming Wave

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

Island

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

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.

Bushwhack

Choose one —
• Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
• Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

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.

Kiora, Behemoth Beckoner

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

Simic Sky Swallower

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

Genesis Wave

Reveal the top X cards of your library. You may put any number of permanent cards with mana value X or less from among them onto the battlefield. Then put all cards revealed this way that weren't put onto the battlefield into your graveyard.

Mind Stone

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

Fanatic of Rhonas

{T}: Add {G}.
Ferocious — {T}: Add {G}{G}{G}{G}. Activate only if you control a creature with power 4 or greater.
Eternalize {2}{G}{G} ({2}{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 Snake Druid 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.)

Troyan, Gutsy Explorer

{T}: Add {G}{U}. Spend this mana only to cast spells with mana value 5 or greater or spells with {X} in their mana costs.
{U}, {T}: Draw a card, then discard a card.

Search for Tomorrow

Search your library for a basic land card, put it onto the battlefield, then shuffle.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Rewind

Counter target spell. Untap up to four lands.

Negate

Dark Depths

Dark Depths enters the battlefield with ten ice counters on it.
{3}: Remove an ice counter from Dark Depths.
When Dark Depths has no ice counters on it, sacrifice it. If you do, create Marit Lage, a legendary 20/20 black Avatar creature token with flying and indestructible.

Nimbus Swimmer

Flying
Nimbus Swimmer enters the battlefield with X +1/+1 counters on it.

Sol Ring

Imoti, Celebrant of Bounty

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Spells you cast with mana value 6 or greater have cascade.

Decisive Denial

Choose one —
• Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)
• Counter target noncreature spell unless its controller pays {3}.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Natural Reclamation

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Destroy target artifact or enchantment.

Counterspell

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Traverse the Outlands

Search your library for up to X basic land cards, where X is the greatest power among creatures you control. Put those cards onto the battlefield tapped, then shuffle.

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.

Wild Growth

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.

Benthic Anomaly

Devoid
When you cast this spell, for each opponent, choose a creature that player controls. Create a token that's a copy of one of those creatures, except its power is equal to the total power of those creatures, its toughness is equal to the total toughness of those creatures, and it's a colorless Eldrazi creature.

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Plasm Capture

Counter target spell. At the beginning of your next precombat main phase, add X mana in any combination of colors, where X is that spell's mana value.

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.

Broken Bond

Destroy target artifact or enchantment. You may put a land card from your hand onto the battlefield.

Kiora's Follower

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.

Maelstrom Colossus

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Goreclaw, Terror of Qal Sisma

Creature spells you cast with power 4 or greater cost {2} less to cast.
Whenever Goreclaw, Terror of Qal Sisma attacks, each creature you control with power 4 or greater gets +1/+1 and gains trample until end of turn.

Thought Vessel

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

Explosive Vegetation

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Rogue's Passage

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

Murkfiend Liege

Other green creatures you control get +1/+1.
Other blue creatures you control get +1/+1.
Untap all green and/or blue creatures you control during each other player's untap step.

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.

Explore

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

Tatyova, Benthic Druid

Landfall — Whenever a land enters the battlefield under your control, you gain 1 life and draw a card.

Kefnet's Monument

Blue creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature an opponent controls doesn't untap during its controller's next untap step.

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.

Harmonize

Rampant Growth

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

Voyaging Satyr

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.

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.)

Reef Worm

When Reef Worm dies, create a 3/3 blue Fish creature token with "When this creature dies, create a 6/6 blue Whale creature token with 'When this creature dies, create a 9/9 blue Kraken creature token.'"

Ilysian Caryatid

{T}: Add one mana of any color. If you control a creature with power 4 or greater, add two mana of any one color instead.

The Watcher in the Water

The Watcher in the Water enters the battlefield tapped with nine stun counters on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Whenever you draw a card during an opponent's turn, create a 1/1 blue Tentacle creature token.
Whenever a Tentacle you control dies, untap up to one target Kraken and put a stun counter on up to one target nonland permanent.

Arcane Signet

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

Deep-Sea Kraken

Deep-Sea Kraken can't be blocked.
Suspend 9—{2}{U} (Rather than cast this card from your hand, you may pay {2}{U} and exile it with nine time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)
Whenever an opponent casts a spell, if Deep-Sea Kraken is suspended, remove a time counter from it.

The Key to the Vault

Whenever equipped creature deals combat damage to a player, look at that many cards from the top of your library. You may exile a nonland card from among them. Put the rest on the bottom of your library in a random order. You may cast the exiled card without paying its mana cost.
Equip {2}{U}

Gilded Lotus

Fertile Ground

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Fleet Swallower

Whenever Fleet Swallower attacks, target player mills half their library, rounded up.

Out of Air

This spell costs {2} less to cast if it targets a creature spell.
Counter target spell.

Stormsurge Kraken

Hexproof
Lieutenant — As long as you control your commander, Stormsurge Kraken gets +2/+2 and has "Whenever Stormsurge Kraken becomes blocked, you may draw two cards."

Thryx, the Sudden Storm

Flash
Flying
Spells you cast with mana value 5 or greater cost {1} less to cast and can't be countered.

Engulf the Shore

Return to their owners' hands all creatures with toughness less than or equal to the number of Islands you control.

Rush of Knowledge

Draw cards equal to the highest mana value among permanents you control.

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.)

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.

Forceful Denial

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Counter target spell.

Growth Spiral

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

Ingenuity Engine

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
{1}, {T}, Sacrifice an artifact: Return target artifact you control to its owner's hand.

Serpent of Yawning Depths

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

Green Sun's Twilight

Reveal the top X plus one cards of your library. Choose a creature card and/or a land card from among them. Put those cards into your hand and the rest on the bottom of your library in a random order. If X is 5 or more, instead put the chosen cards onto the battlefield or into your hand and the rest on the bottom of your library in a random order.

Khalni Territory

Khalni Territory enters the battlefield tapped.
{T}: Add {G}.

Khalni Ambush

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Khalni Ambush // Khalni Territory

Displacement Wave

Return all nonland permanents with mana value X or less to their owners' hands.