Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Paragon of Gathering Mists

Other blue creatures you control get +1/+1.
{U}, {T}: Another target blue creature you control gains flying until end of turn.

Sol Ring

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.)

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Strata Scythe

Imprint — When Strata Scythe enters the battlefield, search your library for a land card, exile it, then shuffle.
Equipped creature gets +1/+1 for each land on the battlefield with the same name as the exiled card.
Equip {3}

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.

Crypsis

Target creature you control gains protection from creatures your opponents control until end of turn. Untap it.

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.

High Tide

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

Sleep

Tap all creatures target player controls. Those creatures don't untap during that player's next untap step.

Waterknot

Enchant creature
When Waterknot enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Invisibility

Enchant creature
Enchanted creature can't be blocked except by Walls.

Whelming Wave

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

Aetherize

Return all attacking creatures to their owner's hand.

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."

Sigiled Starfish

{T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Crippling Chill

Tap target creature. It doesn't untap during its controller's next untap step.
Draw a card.

Take Flight

Enchant creature
Enchanted creature gets +1/+0 and has flying and "Whenever this creature attacks, draw a card."

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Charmed Sleep

Enchant creature
When Charmed Sleep enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Island

Eel Umbra

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature gets +1/+1.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Claustrophobia

Enchant creature
When Claustrophobia enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Ghostly Touch

Enchant creature
Enchanted creature has "Whenever this creature attacks, you may tap or untap target permanent."

Sword of Vengeance

Equipped creature gets +2/+0 and has first strike, vigilance, trample, and haste.
Equip {3}

Flow of Knowledge

Draw a card for each Island you control, then discard two cards.

Palladium Myr

Divination

Trip Noose

Blustersquall

Tap target creature you don't control.
Overload {3}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Guardian of Tazeem

Flying
Landfall — Whenever a land enters the battlefield under your control, tap target creature an opponent controls. If that land is an Island, that creature doesn't untap during its controller's next untap step.

Stonybrook Angler

{1}{U}, {T}: You may tap or untap target creature.

Flood

{U}{U}: Tap target creature without flying.

Dreamshackle Geist

Flying
At the beginning of combat on your turn, choose up to one —
• Tap target creature.
• Target creature doesn't untap during its controller's next untap step.

Colossal Whale

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever Colossal Whale attacks, you may exile target creature defending player controls until Colossal Whale leaves the battlefield. (That creature returns under its owner's control.)

Loxodon Warhammer

Equipped creature gets +3/+0 and has trample and lifelink.
Equip {3}

Sky Diamond

Sky Diamond enters the battlefield tapped.
{T}: Add {U}.

Apprentice Wizard

Negate

Pacification Array

{2}, {T}: Tap target artifact or creature.

Keep Safe

Counter target spell that targets a permanent you 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.

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Turn Aside

Counter target spell that targets a permanent you control.

Defiler of Dreams

Flying
As an additional cost to cast blue permanent spells, you may pay 2 life. Those spells cost {U} less to cast if you paid life this way. This effect reduces only the amount of blue mana you pay.
Whenever you cast a blue permanent spell, draw a card.

Myriad Landscape

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.

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Haunted Cloak

Equipped creature has vigilance, trample, and haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Silver Myr

Cartouche of Knowledge

Enchant creature you control
When Cartouche of Knowledge enters the battlefield, draw a card.
Enchanted creature gets +1/+1 and has flying.

Tolarian Kraken

Whenever you draw a card, you may pay {1}. When you do, you may tap or untap target creature.

Callaphe, Beloved of the Sea

Callaphe's power is equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
Creatures and enchantments you control have "Spells your opponents cast that target this permanent cost {1} more to cast."

Rush of Knowledge

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

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.

Combat Research

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
As long as enchanted creature is legendary, it gets +1/+1 and has ward {1}. (Whenever enchanted creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Swiftfoot Boots

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

Arcane Signet

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

Encrust

Enchant artifact or creature
Enchanted permanent doesn't untap during its controller's untap step and its activated abilities can't be activated.

Mind Stone

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

Frantic Search

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

Commander's Sphere

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

Choking Tethers

Tap up to four target creatures.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle Choking Tethers, you may tap target creature.

Verity Circle

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.
{4}{U}: Tap target creature without flying.

Counterspell

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.

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.

Quiet Contemplation

Whenever you cast a noncreature spell, you may pay {1}. If you do, tap target creature an opponent controls and it doesn't untap during its controller's next untap step.