Gain control of target spell. You may choose new targets for it. (If that spell becomes a permanent, it enters the battlefield under your control.)
{6}{W}
Approach of the Second Sun
Sorcery
If this spell was cast from your hand and you've cast another spell named Approach of the Second Sun this game, you win the game. Otherwise, put Approach of the Second Sun into its owner's library seventh from the top and you gain 7 life.
{2}
Arcane Signet
Artifact
{T}: Add one mana of any color in your commander's color identity.
{W}{U}
Azorius Charm
Instant
Choose one --
• Creatures you control gain lifelink until end of turn.
• Draw a card.
• Put target attacking or blocking creature on top of its owner's library.
--
Azorius Guildgate
Land - Gate
Azorius Guildgate enters the battlefield tapped.
{T}: Add {W} or {U}.
{U}
Blustersquall
Instant
Tap target creature you don't control.
Overload {3}{U} (You may cast this spell for its overload cost. If you do, change its text by replacing all instances of "target" with "each.")
{U}{U}
Boomerang
Instant
Return target permanent to its owner's hand.
{U}
Brainstorm
Instant
Draw three cards, then put two cards from your hand on top of your library in any order.
--
Cavern of Souls
Land
As Cavern of Souls enters the battlefield, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.
{W}{W}
Celestial Flare
Instant
Target player sacrifices an attacking or blocking creature.
{2}{U}
Clear the Mind
Sorcery
Target player shuffles their graveyard into their library.
Draw a card.
--
Command Tower
Land
{T}: Add one mana of any color in your commander's color identity.
{3}
Commander's Sphere
Artifact
{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.
{2}{U}{U}
Concentrate
Sorcery
Draw three cards.
{U}{U}
Counterspell
Instant
Counter target spell.
--
Darksteel Citadel
Artifact Land
Indestructible
{T}: Add {C}.
{2}{U}
Deeproot Waters
Enchantment
Whenever you cast a Merfolk spell, create a 1/1 blue Merfolk creature token with hexproof. (A creature with hexproof can't be the target of spells or abilities your opponents control.)
{1}{U}
Deliberate
Instant
Scry 2, then draw a card.
{6}{W}
Devout Invocation
Sorcery
Tap any number of untapped creatures you control. Create a 4/4 white Angel creature token with flying for each creature tapped this way.
{1}{W}
Disenchant
Instant
Destroy target artifact or enchantment.
{2}{U}
Drowner of Secrets
Creature - Merfolk Wizard
Tap an untapped Merfolk you control: Target player mills a card.
1 /
3
{1}
Elixir of Immortality
Artifact
{2}, {T}: You gain 5 life. Shuffle Elixir of Immortality and your graveyard into their owner's library.
{W}
Emerge Unscathed
Instant
Target creature you control gains protection from the color of your choice until end of turn.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)
--
Evolving Wilds
Land
{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{1}{W}
Feat of Resistance
Instant
Put a +1/+1 counter on target creature you control. It gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)
{4}
Firemind Vessel
Artifact
Firemind Vessel enters the battlefield tapped.
{T}: Add two mana of different colors.
--
Glacial Fortress
Land
Glacial Fortress enters the battlefield tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.
{W}
Gods Willing
Instant
Target creature you control gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)
Scry 1.
{1}{U}
Hands of Binding
Sorcery
Tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)
{U}{U}
Harbinger of the Tides
Creature - Merfolk Wizard
You may cast Harbinger of the Tides as though it had flash if you pay {2} more to cast it. (You may cast it any time you could cast an instant.)
When Harbinger of the Tides enters the battlefield, you may return target tapped creature an opponent controls to its owner's hand.
2 /
2
{2}{W}
Harpoon Sniper
Creature - Merfolk Archer
{W}, {T}: Harpoon Sniper deals X damage to target attacking or blocking creature, where X is the number of Merfolk you control.
2 /
2
{3}{W}{W}{W}
Hour of Revelation
Sorcery
This spell costs {3} less to cast if there are ten or more nonland permanents on the battlefield.
Destroy all nonland permanents.
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
--
Island
Basic Land - Island
({T}: Add {U}.)
{1}{W}
Judge of Currents
Creature - Merfolk Wizard
Whenever a Merfolk you control becomes tapped, you may gain 1 life.
1 /
1
{1}{U}{U}
Kopala, Warden of Waves
Legendary Creature - Merfolk Wizard
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.
2 /
2
{3}{U}
Master of Waves
Creature - Merfolk Wizard
Protection from red
Elemental creatures you control get +1/+1.
When Master of Waves enters the battlefield, create a number of 1/0 blue Elemental creature tokens equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
2 /
1
{U}{U}
Master of the Pearl Trident
Creature - Merfolk
Other Merfolk creatures you control get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)
2 /
2
--
Meandering River
Land
Meandering River enters the battlefield tapped.
{T}: Add {W} or {U}.
{1}{U}{U}
Merfolk Sovereign
Creature - Merfolk Noble
Other Merfolk creatures you control get +1/+1.
{T}: Target Merfolk creature can't be blocked this turn.
2 /
2
{U}
Merfolk Windrobber
Creature - Merfolk Rogue
Flying
Whenever Merfolk Windrobber deals combat damage to a player, that player mills a card. (They put the top card of their library into their graveyard.)
Sacrifice Merfolk Windrobber: Draw a card. Activate only if an opponent has eight or more cards in their graveyard.
1 /
1
{1}{U}
Merrow Commerce
Tribal Enchantment - Merfolk
At the beginning of your end step, untap all Merfolk you control.
{U}
Miscast
Instant
Counter target instant or sorcery spell unless its controller pays {3}.
--
Myriad Landscape
Land
Myriad Landscape enters the battlefield tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.
{3}{W}{U}
Noyan Dar, Roil Shaper
Legendary Creature - Merfolk Ally
Whenever you cast an instant or sorcery spell, you may put three +1/+1 counters on target land you control. If you do, that land becomes a 0/0 Elemental creature with haste that's still a land.
4 /
4
{U}
Opt
Instant
Scry 1.
Draw a card.
--
Path of Ancestry
Land
Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
--
Plains
Basic Land - Plains
({T}: Add {W}.)
--
Plains
Basic Land - Plains
({T}: Add {W}.)
--
Plains
Basic Land - Plains
({T}: Add {W}.)
--
Plains
Basic Land - Plains
({T}: Add {W}.)
--
Plains
Basic Land - Plains
({T}: Add {W}.)
--
Plains
Basic Land - Plains
({T}: Add {W}.)
--
Plains
Basic Land - Plains
({T}: Add {W}.)
--
Plains
Basic Land - Plains
({T}: Add {W}.)
{3}{W}{W}
Planar Outburst
Sorcery
Destroy all nonland creatures.
Awaken 4--{5}{W}{W}{W} (If you cast this spell for {5}{W}{W}{W}, also put four +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)
{U}
Ponder
Sorcery
Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.
{U}
Preordain
Sorcery
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.)
{1}{U}
Quench
Instant
Counter target spell unless its controller pays {2}.
{1}{U}
Refocus
Instant
Untap target creature.
Draw a card.
--
Reliquary Tower
Land
You have no maximum hand size.
{T}: Add {C}.
{1}{W}
Revoke Existence
Sorcery
Exile target artifact or enchantment.
{1}{U}
River Sneak
Creature - Merfolk Warrior
River Sneak can't be blocked.
Whenever another Merfolk enters the battlefield under your control, River Sneak gets +1/+1 until end of turn.
1 /
1
{2}{U}
Sage of Fables
Creature - Merfolk Wizard
Each other Wizard creature you control enters the battlefield with an additional +1/+1 counter on it.
{2}, Remove a +1/+1 counter from a creature you control: Draw a card.
2 /
2
{1}{U}
Sejiri Merfolk
Creature - Merfolk Soldier
As long as you control a Plains, Sejiri Merfolk has first strike and lifelink. (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)
2 /
1
{1}{U}{U}
Sigil Tracer
Creature - Merfolk Wizard
{1}{U}, Tap two untapped Wizards you control: Copy target instant or sorcery spell. You may choose new targets for the copy.
2 /
2
{W}
Silence
Instant
Your opponents can't cast spells this turn.
{1}
Sol Ring
Artifact
{T}: Add {C}{C}.
{1}{W}
Spirit Mantle
Enchantment - Aura
Enchant creature
Enchanted creature gets +1/+1 and has protection from creatures.
{4}{U}{U}
Stolen Identity
Sorcery
Create a token that's a copy of target artifact or creature.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)
{1}{U}
Stonybrook Banneret
Creature - Merfolk Wizard
Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Merfolk spells and Wizard spells you cast cost {1} less to cast.
1 /
1
{2}{W}
Stonybrook Schoolmaster
Creature - Merfolk Wizard
Whenever Stonybrook Schoolmaster becomes tapped, you may create a 1/1 blue Merfolk Wizard creature token.
1 /
2
{3}{W}
Summon the School
Tribal Sorcery - Merfolk
Create two 1/1 blue Merfolk Wizard creature tokens.
Tap four untapped Merfolk you control: Return Summon the School from your graveyard to your hand.
{2}
Sword of the Animist
Legendary Artifact - Equipment
Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}
{W}{U}
Sygg, River Guide
Legendary Creature - Merfolk Wizard
Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
{1}{W}: Target Merfolk you control gains protection from the color of your choice until end of turn.
2 /
2
{2}{U}{U}
Talrand, Sky Summoner
Legendary Creature - Merfolk Wizard
Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.
2 /
2
{2}{W}
Terra Eternal
Enchantment
All lands have indestructible.
{U}{U}
Tidebinder Mage
Creature - Merfolk Wizard
When Tidebinder Mage enters the battlefield, tap target red or green creature an opponent controls. That creature doesn't untap during its controller's untap step for as long as you control Tidebinder Mage.
2 /
2
--
Tranquil Cove
Land
Tranquil Cove enters the battlefield tapped.
When Tranquil Cove enters the battlefield, you gain 1 life.
{T}: Add {W} or {U}.
{U}
Triton Shorestalker
Creature - Merfolk Rogue
Triton Shorestalker can't be blocked.
1 /
1
{U}
Unsummon
Instant
Return target creature to its owner's hand.
{2}{U}
Unwind
Instant
Counter target noncreature spell. Untap up to three lands.
{U}
Vapor Snag
Instant
Return target creature to its owner's hand. Its controller loses 1 life.
{3}{W}
Veteran of the Depths
Creature - Merfolk Soldier
Whenever Veteran of the Depths becomes tapped, you may put a +1/+1 counter on it.
2 /
2
{U}
Void Snare
Sorcery
Return target nonland permanent to its owner's hand.
{2}{U}
Wake Thrasher
Creature - Merfolk Soldier
Whenever a permanent you control becomes untapped, Wake Thrasher gets +1/+1 until end of turn.
1 /
1
--
Wanderwine Hub
Land
As Wanderwine Hub enters the battlefield, you may reveal a Merfolk card from your hand. If you don't, Wanderwine Hub enters the battlefield tapped.
{T}: Add {W} or {U}.
{1}
Wayfarer's Bauble
Artifact
{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.