For each attacking creature, its owner puts it on the top or bottom of their library.
{3}{U}{U}{U}
Arcanis the Omnipotent
Legendary Creature - Wizard
{T}: Draw three cards.
{2}{U}{U}: Return Arcanis the Omnipotent to its owner's hand.
3 /
4
{2}{U}{U}
Archaeomancer
Creature - Human Wizard
When Archaeomancer enters the battlefield, return target instant or sorcery card from your graveyard to your hand.
1 /
2
{4}{U}{U}
Archetype of Imagination
Enchantment Creature - Human Wizard
Creatures you control have flying.
Creatures your opponents control lose flying and can't have or gain flying.
3 /
2
{6}
Caged Sun
Artifact
As Caged Sun enters the battlefield, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.
{2}{U}
Chasm Skulker
Creature - Squid Horror
Whenever you draw a card, put a +1/+1 counter on Chasm Skulker.
When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)
1 /
1
{3}
Circuit Mender
Artifact Creature - Insect
When Circuit Mender enters the battlefield, you gain 2 life.
When Circuit Mender leaves the battlefield, draw a card.
2 /
3
{U}
Clockspinning
Instant
Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Choose a counter on target permanent or suspended card. Remove that counter from that permanent or card or put another of those counters on it.
{5}
Conjurer's Closet
Artifact
At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.
{4}{U}{U}
Consecrated Sphinx
Creature - Sphinx
Flying
Whenever an opponent draws a card, you may draw two cards.
4 /
6
{2}{U}
Copy Enchantment
Enchantment
You may have Copy Enchantment enter the battlefield as a copy of any enchantment on the battlefield.
{3}
Crawlspace
Artifact
No more than two creatures can attack you each combat.
{1}{U}
Cyclonic Rift
Instant
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.")
{4}{U}{U}
Deadeye Navigator
Creature - Spirit
Soulbond (You may pair this creature with another unpaired creature when either enters the battlefield. They remain paired for as long as you control both of them.)
As long as Deadeye Navigator is paired with another creature, each of those creatures has "{1}{U}: Exile this creature, then return it to the battlefield under your control."
5 /
5
{2}{U}{U}
Dissipation Field
Enchantment
Whenever a permanent deals damage to you, return it to its owner's hand.
{U}
Dizzy Spell
Instant
Target creature gets -3/-0 until end of turn.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)
{2}{U}
Drift of Phantasms
Creature - Spirit
Defender (This creature can't attack.)
Flying
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)
0 /
5
{2}{U}
Estrid's Invocation
Enchantment
You may have Estrid's Invocation enter the battlefield as a copy of an enchantment you control, except it has "At the beginning of your upkeep, you may exile this enchantment. If you do, return it to the battlefield under its owner's control."
{4}{U}{U}
Extravagant Replication
Enchantment
At the beginning of your upkeep, create a token that's a copy of another target nonland permanent you control.
{2}{U}
Fabricate
Sorcery
Search your library for an artifact card, reveal it, put it into your hand, then shuffle.
{3}
Farfinder
Creature - Fox
Vigilance
When Farfinder enters the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
1 /
1
{1}{U}
Fblthp, the Lost
Legendary Creature - Homunculus
When Fblthp, the Lost enters the battlefield, draw a card. If it entered from your library or was cast from your library, draw two cards instead.
When Fblthp becomes the target of a spell, shuffle Fblthp into its owner's library.
1 /
1
{3}{U}
Floodgate
Creature - Wall
Defender (This creature can't attack.)
When Floodgate has flying, sacrifice it.
When Floodgate leaves the battlefield, it deals damage equal to half the number of Islands you control, rounded down, to each nonblue creature without flying.
0 /
5
{3}{U}{U}
Followed Footsteps
Enchantment - Aura
Enchant creature
At the beginning of your upkeep, create a token that's a copy of enchanted creature.
{1}{U}
Frogify
Enchantment - Aura
Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1. (It loses all other card types and creature types.)
{5}
Gauntlet of Power
Artifact
As Gauntlet of Power enters the battlefield, choose a color.
Creatures of the chosen color get +1/+1.
Whenever a basic land is tapped for mana of the chosen color, its controller adds an additional one mana of that color.
{3}{U}
Gigantoplasm
Creature - Shapeshifter
You may have Gigantoplasm enter the battlefield as a copy of any creature on the battlefield, except it has "{X}: This creature has base power and toughness X/X."
0 /
0
{4}
Helm of the Host
Legendary Artifact - Equipment
At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}
{U}
High Tide
Instant
Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.
{2}{U}{U}
Illusionist's Gambit
Instant
Cast this spell only during the declare blockers step on an opponent's turn.
Remove all attacking creatures from combat and untap them. After this phase, there is an additional combat phase. Each of those creatures attacks that combat if able. They can't attack you or planeswalkers you control that combat.
{2}{U}
Imprisoned in the Moon
Enchantment - Aura
Enchant creature, land, or planeswalker
Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.
--
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}.)
--
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}.)
{2}
Isochron Scepter
Artifact
Imprint -- When Isochron Scepter enters the battlefield, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.
{3}{U}
Jalira, Master Polymorphist
Legendary Creature - Human Wizard
{2}{U}, {T}, Sacrifice another creature: Reveal cards from the top of your library until you reveal a nonlegendary creature card. Put that card onto the battlefield and the rest on the bottom of your library in a random order.
2 /
2
{4}{U}{U}
Kapsho Kitefins
Creature - Fish
Flying
Whenever Kapsho Kitefins or another creature enters the battlefield under your control, tap target creature an opponent controls.
3 /
3
{1}{U}
Kasmina's Transmutation
Enchantment - Aura
Enchant creature
Enchanted creature loses all abilities and has base power and toughness 1/1.
{2}{U}{U}
Leyline of Anticipation
Enchantment
If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.
--
Magosi, the Waterveil
Land
Magosi, the Waterveil enters the battlefield tapped.
{T}: Add {U}.
{U}, {T}: Put an eon counter on Magosi, the Waterveil. Skip your next turn.
{T}, Remove an eon counter from Magosi, the Waterveil and return it to its owner's hand: Take an extra turn after this one.
{2}{U}{U}
Mechanized Production
Enchantment - Aura
Enchant artifact you control
At the beginning of your upkeep, create a token that's a copy of enchanted artifact. Then if you control eight or more artifacts with the same name as one another, you win the game.
{3}{U}{U}
Mesmerizing Benthid
Creature - Octopus
When Mesmerizing Benthid enters the battlefield, create two 0/2 blue Illusion creature tokens with "Whenever this creature blocks a creature, that creature doesn't untap during its controller's next untap step."
Mesmerizing Benthid has hexproof as long as you control an Illusion.
4 /
5
{7}
Meteor Golem
Artifact Creature - Golem
When Meteor Golem enters the battlefield, destroy target nonland permanent an opponent controls.
3 /
3
{3}{U}
Mirrorhall Mimic
Creature - Spirit
You may have Mirrorhall Mimic enter the battlefield as a copy of any creature on the battlefield, except it's a Spirit in addition to its other types.
Disturb {3}{U}{U} (You may cast this card from your graveyard transformed for its disturb cost.)
0 /
0
--
Ghastly Mimicry
Enchantment - Aura
Enchant creature
At the beginning of your upkeep, create a token that's a copy of enchanted creature, except it's a Spirit in addition to its other types.
If Ghastly Mimicry would be put into a graveyard from anywhere, exile it instead.
0 /
0
{1}{U}{U}
Mirrormade
Enchantment
You may have Mirrormade enter the battlefield as a copy of any artifact or enchantment on the battlefield.
{U}{U}
Muddle the Mixture
Instant
Counter target instant or sorcery spell.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)
{7}
Myr Battlesphere
Artifact Creature - Myr Construct
When Myr Battlesphere enters the battlefield, create four 1/1 colorless Myr artifact creature tokens.
Whenever Myr Battlesphere attacks, you may tap X untapped Myr you control. If you do, Myr Battlesphere gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.
4 /
7
{1}{U}{U}
Nadir Kraken
Creature - 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.
2 /
3
{4}
Panharmonicon
Artifact
If an artifact or creature entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
{2}{U}
Paradox Haze
Enchantment - Aura
Enchant player
At the beginning of enchanted player's first upkeep each turn, that player gets an additional upkeep step after this step.
{4}
Pierce Strider
Artifact Creature - Phyrexian Construct
When Pierce Strider enters the battlefield, target opponent loses 3 life.
3 /
3
{3}
Pilgrim's Eye
Artifact Creature - Thopter
Flying
When Pilgrim's Eye enters the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
1 /
1
{2}{U}
Propaganda
Enchantment
Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.
--
Reliquary Tower
Land
You have no maximum hand size.
{T}: Add {C}.
{3}
Replicating Ring
Snow Artifact
{T}: Add one mana of any color.
At the beginning of your upkeep, put a night counter on Replicating Ring. Then if it has eight or more night counters on it, remove all of them and create eight colorless snow artifact tokens named Replicated Ring with "{T}: Add one mana of any color."
{3}
Rings of Brighthearth
Artifact
Whenever you activate an ability, if it isn't a mana ability, you may pay {2}. If you do, copy that ability. You may choose new targets for the copy.
{2}{U}{U}
Rite of Replication
Sorcery
Kicker {5} (You may pay an additional {5} as you cast this spell.)
Create a token that's a copy of target creature. If this spell was kicked, create five of those tokens instead.
{3}{U}
Sakashima of a Thousand Faces
Legendary Creature - Human Rogue
You may have Sakashima of a Thousand Faces enter the battlefield as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)
3 /
1
--
Sand Silos
Land
Sand Silos enters the battlefield tapped.
You may choose not to untap Sand Silos during your untap step.
At the beginning of your upkeep, if Sand Silos is tapped, put a storage counter on it.
{T}, Remove any number of storage counters from Sand Silos: Add {U} for each storage counter removed this way.
{5}{U}{U}
Scourge of Fleets
Creature - Kraken
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.
6 /
6
{4}{U}{U}
Shipbreaker Kraken
Creature - 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.
6 /
6
{3}
Skittering Surveyor
Artifact Creature - Construct
When Skittering Surveyor enters the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
1 /
2
{4}
Solemn Simulacrum
Artifact Creature - Golem
When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.
2 /
2
{6}{U}{U}
Sphinx of the Second Sun
Creature - Sphinx
Flying
At the beginning of your postcombat main phase, there is an additional beginning phase after this phase. (The beginning phase includes the untap, upkeep, and draw steps.)
6 /
6
{X}{2}{U}
Stroke of Genius
Instant
Target player draws X cards.
{3}{U}
Thassa, Deep-Dwelling
Legendary Enchantment Creature - God
Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.
6 /
5
--
Thawing Glaciers
Land
Thawing Glaciers enters the battlefield tapped.
{1}, {T}: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. Return Thawing Glaciers to its owner's hand at the beginning of the next cleanup step.
At the beginning of your draw step, draw an additional card.
Spells you cast cost {1} less to cast.
Creatures you control get +1/+1.
{1}{U}
The Reality Chip
Legendary Artifact Creature - Equipment Jellyfish
You may look at the top card of your library any time.
As long as The Reality Chip is attached to a creature, you may play lands and cast spells from the top of your library.
Reconfigure {2}{U} ({2}{U}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)
0 /
4
--
Tolaria West
Land
Tolaria West enters the battlefield tapped.
{T}: Add {U}.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with mana value 0, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)
{2}{U}
War Tax
Enchantment
{X}{U}: This turn, creatures can't attack unless their controller pays {X} for each attacking creature they control.
{1}{U}
Watcher for Tomorrow
Creature - Human Wizard
Hideaway 4 (When this creature enters the battlefield, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Watcher for Tomorrow enters the battlefield tapped.
When Watcher for Tomorrow leaves the battlefield, put the exiled card into its owner's hand.
2 /
1
{2}{U}
Web of Inertia
Enchantment
At the beginning of combat on each opponent's turn, that player may exile a card from their graveyard. If the player doesn't, creatures they control can't attack you this turn.
{U}
Witness Protection
Enchantment - Aura
Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)
{U}
Wizard Class
Enchantment - Class
(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.