Dismiss into Dream

Each creature your opponents control is an Illusion in addition to its other types and has "When this creature becomes the target of a spell or ability, sacrifice it."

Elvish Piper

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

Myr Galvanizer

Other Myr creatures you control get +1/+1.
{1}, {T}: Untap each other Myr you control.

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Vodalian Hexcatcher

Flash
Other Merfolk you control get +1/+1.
Sacrifice a Merfolk: Counter target noncreature spell unless its controller pays {1}.

Winged Sliver

Gor Muldrak, Amphinologist

You and permanents you control have protection from Salamanders.
At the beginning of your end step, each player who controls the fewest creatures creates a 4/3 blue Salamander Warrior creature token.

Rejuvenating Springs

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

Avenger of Zendikar

When Avenger of Zendikar enters the battlefield, create a 0/1 green Plant creature token for each land you control.
Landfall — Whenever a land enters the battlefield under your control, you may put a +1/+1 counter on each Plant creature you control.

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.

Collective Restraint

Domain — Creatures can't attack you unless their controller pays {X} for each creature they control that's attacking you, where X is the number of basic land types among lands you control.

Lord of Atlantis

Other Merfolk get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

Priest of Titania

{T}: Add {G} for each Elf on the battlefield.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Herald of Hoofbeats

Horsemanship (This creature can't be blocked except by creatures with horsemanship.)
Other Knights you control have horsemanship.

Kopala, Warden of Waves

Spells your opponents cast that target a Merfolk you control cost {2} more to cast.
Abilities your opponents activate that target a Merfolk you control cost {2} more to activate.

Lullmage Mentor

Whenever a spell or ability you control counters a spell, you may create a 1/1 blue Merfolk creature token.
Tap seven untapped Merfolk you control: Counter target spell.

Kodama's Reach

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.

Sol Ring

Arcane Signet

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

Mass Appeal

Heroic Intervention

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

Descendants' Path

At the beginning of your upkeep, reveal the top card of your library. If it's a creature card that shares a creature type with a creature you control, you may cast it without paying its mana cost. If you don't cast it, put it on the bottom of your library.

Counterspell

Leaf-Crowned Elder

Kinship — At the beginning of your upkeep, you may look at the top card of your library. If it shares a creature type with Leaf-Crowned Elder, you may reveal it. If you do, you may play that card without paying its mana cost.

Mithril Coat

Flash
Indestructible
When Mithril Coat enters the battlefield, attach it to target legendary creature you control.
Equipped creature has indestructible.
Equip {3}

Command Tower

Rogue's Passage

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

Endless Evil

Enchant creature you control
At the beginning of your upkeep, create a token that's a copy of enchanted creature, except the token is 1/1.
When enchanted creature dies, if that creature was a Horror, return Endless Evil to its owner's hand.

Urza's Workshop

{T}: Add {C}.
Metalcraft — {T}: Add {C} for each Urza's land you control. Activate only if you control three or more artifacts.

Tidechannel Pathway

Barkchannel Pathway

Barkchannel Pathway // Tidechannel Pathway

Elvish Archdruid

Other Elf creatures you control get +1/+1.
{T}: Add {G} for each Elf you control.

Pact of Negation

Counter target spell.
At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

Overflowing Basin

Feline Sovereign

Other Cats you control get +1/+1 and have protection from Dogs.
Whenever one or more Cats you control deal combat damage to a player, destroy up to one target artifact or enchantment that player controls.

Svyelun of Sea and Sky

Svyelun of Sea and Sky has indestructible as long as you control at least two other Merfolk.
Whenever Svyelun attacks, draw a card.
Other Merfolk you control have ward {1}. (Whenever another Merfolk you control becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Full Moon's Rise

Werewolf creatures you control get +1/+0 and have trample.
Sacrifice Full Moon's Rise: Regenerate all Werewolf creatures you control.

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.

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}.

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Synchronous Sliver

Forest

Exotic Orchard

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

Commander's Plate

Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity.
Equip commander {3}
Equip {5}

Timber Protector

Other Treefolk creatures you control get +1/+1.
Other Treefolk and Forests you control have indestructible.

Island

Kumena, Tyrant of Orazca

Tap another untapped Merfolk you control: Kumena, Tyrant of Orazca can't be blocked this turn.
Tap three untapped Merfolk you control: Draw a card.
Tap five untapped Merfolk you control: Put a +1/+1 counter on each Merfolk you control.

Beast Within

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

Absorb Identity

Return target creature to its owner's hand. You may have Shapeshifters you control become copies of that creature until end of turn.

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Omo, Queen of Vesuva

Whenever Omo, Queen of Vesuva enters the battlefield or attacks, put an everything counter on each of up to one target land and up to one target creature.
Each land with an everything counter on it is every land type in addition to its other types.
Each nonland creature with an everything counter on it is every creature type.

Call to the Kindred

Enchant creature
At the beginning of your upkeep, you may look at the top five cards of your library. If you do, you may put a creature card that shares a creature type with enchanted creature from among them onto the battlefield, then you put the rest of those cards on the bottom of your library in any order.

Urza's Factory

{T}: Add {C}.
{7}, {T}: Create a 2/2 colorless Assembly-Worker artifact creature token.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Raise the Palisade

Choose a creature type. Return all creatures that aren't of the chosen type to their owners' hands.

Roaming Throne

Ward {2}
As Roaming Throne enters the battlefield, choose a creature type.
Roaming Throne is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Biowaste Blob

Oozes you control get +1/+1.
At the beginning of your upkeep, if you control a commander, create a token that's a copy of Biowaste Blob.

Simic Growth Chamber

Simic Growth Chamber enters the battlefield tapped.
When Simic Growth Chamber enters the battlefield, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Pongify

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

Tropical Island

Cultivate

Merrow Commerce

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

Negate

Lord of the Unreal

Illusion creatures you control get +1/+1 and have hexproof. (They can't be the targets of spells or abilities your opponents control.)

Diffusion Sliver

Whenever a Sliver creature you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Pheres-Band Warchief

Vigilance, trample
Other Centaur creatures you control get +1/+1 and have vigilance and trample.

Whelming Wave

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

Elvish Champion

Other Elf creatures get +1/+1 and have forestwalk. (They can't be blocked as long as defending player controls a Forest.)

Reliquary Tower

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

Multiclass Baldric

Equipped creature has lifelink if you control a Cleric, deathtouch if you control a Rogue, haste if you control a Warrior, and flying if you control a Wizard.
As long as you have a full party, prevent all damage that would be dealt to equipped creature.
Equip {2}

Fierce Guardianship

If you control a commander, you may cast this spell without paying its mana cost.
Counter target noncreature spell.

Sea Gate Loremaster

{T}: Draw a card for each Ally you control.

Hinterland Harbor

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

Merfolk Sovereign

Other Merfolk creatures you control get +1/+1.
{T}: Target Merfolk creature can't be blocked this turn.

Shifting Sliver

Slivers can't be blocked except by Slivers.

Baru, Wurmspeaker

Wurms you control get +2/+2 and have trample.
{7}{G}, {T}: Create a 4/4 green Wurm creature token. This ability costs {X} less to activate, where X is the greatest power among Wurms you control.

Dreamroot Cascade

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

Worldly Tutor

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

Collected Company

Look at the top six cards of your library. Put up to two creature cards with mana value 3 or less from among them onto the battlefield. Put the rest on the bottom of your library in any order.

Willbreaker

Whenever a creature an opponent controls becomes the target of a spell or ability you control, gain control of that creature for as long as you control Willbreaker.

Cyclone Summoner

When Cyclone Summoner enters the battlefield, if you cast it from your hand, return all permanents to their owners' hands except for Giants, Wizards, and lands.