Rattlechains

Flash
Flying
When Rattlechains enters the battlefield, target Spirit gains hexproof until end of turn.
You may cast Spirit spells as though they had flash.

Swiftfoot Boots

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

Rewind

Counter target spell. Untap up to four lands.

Azami, Lady of Scrolls

Tap an untapped Wizard you control: Draw a card.

Myr Galvanizer

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

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.

Stonybrook Banneret

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.

Shapesharer

Changeling (This card is every creature type.)
{2}{U}: Target Shapeshifter becomes a copy of target creature until your next turn.

Stunt Double

Flash
You may have Stunt Double enter the battlefield as a copy of any creature on the battlefield.

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.

Xenograft

As Xenograft enters the battlefield, choose a creature type.
Each creature you control is the chosen type in addition to its other types.

Animal Sanctuary

{T}: Add {C}.
{2}, {T}: Put a +1/+1 counter on target Bird, Cat, Dog, Goat, Ox, or Snake.

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}.

Sol Ring

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.

Shadow Sliver

All Sliver creatures have shadow. (They can block or be blocked by only creatures with shadow.)

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Aetherize

Return all attacking creatures to their owner's hand.

Mirage Mirror

{2}: Mirage Mirror becomes a copy of target artifact, creature, enchantment, or land until end of turn.

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Rooftop Storm

You may pay {0} rather than pay the mana cost for Zombie creature spells you cast.

Thespian's Stage

{T}: Add {C}.
{2}, {T}: Thespian's Stage becomes a copy of target land, except it has this ability.

Wizard's Retort

This spell costs {1} less to cast if you control a Wizard.
Counter target spell.

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.)

Clone Legion

For each creature target player controls, create a token that's a copy of that creature.

Rogue's Passage

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

Mistform Warchief

Creature spells you cast that share a creature type with Mistform Warchief cost {1} less to cast.
{T}: Mistform Warchief becomes the creature type of your choice until end of turn.

Silver Myr

Wing Splicer

When Wing Splicer enters the battlefield, create a 3/3 colorless Phyrexian Golem artifact creature token.
Golem creatures you control have flying.

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Pongify

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

Merrow Harbinger

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
When Merrow Harbinger enters the battlefield, you may search your library for a Merfolk card, reveal it, then shuffle and put that card on top.

Clever Impersonator

You may have Clever Impersonator enter the battlefield as a copy of any nonland permanent on the battlefield.

Obsidian Battle-Axe

Equipped creature gets +2/+1 and has haste.
Whenever a Warrior creature enters the battlefield, you may attach Obsidian Battle-Axe to it.
Equip {3}

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.

Rite of Replication

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.

Heraldic Banner

As Heraldic Banner enters the battlefield, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Merfolk Sovereign

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

Merrow Reejerey

Other Merfolk creatures you control get +1/+1.
Whenever you cast a Merfolk spell, you may tap or untap target permanent.

Seahunter

{3}, {T}: Search your library for a Merfolk permanent card, put it onto the battlefield, then shuffle.

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.

Counterspell

Inundate

Return all nonblue creatures to their owners' hands.

Diviner's Wand

Equipped creature has "Whenever you draw a card, this creature gets +1/+1 and gains flying until end of turn" and "{4}: Draw a card."
Whenever a Wizard creature enters the battlefield, you may attach Diviner's Wand to it.
Equip {3}

Galecaster Colossus

Tap an untapped Wizard you control: Return target nonland permanent you don't control to its owner's hand.

Cloak and Dagger

Equipped creature gets +2/+0 and has shroud. (It can't be the target of spells or abilities.)
Whenever a Rogue creature enters the battlefield, you may attach Cloak and Dagger to it.
Equip {3}

Halimar Depths

Halimar Depths enters the battlefield tapped.
When Halimar Depths enters the battlefield, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

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.

Amoeboid Changeling

Changeling (This card is every creature type.)
{T}: Target creature gains all creature types until end of turn.
{T}: Target creature loses all creature types until end of turn.

Mothdust Changeling

Changeling (This card is every creature type.)
Tap an untapped creature you control: Mothdust Changeling gains flying until end of turn.

Birthing Boughs

{4}, {T}: Create a 2/2 colorless Shapeshifter creature token with changeling. (It has every creature type.)

Master of Waves

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.)

Burnished Hart

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

Universal Automaton

Changeling (This card is every creature type.)

Stoneforge Masterwork

Equipped creature gets +1/+1 for each other creature you control that shares a creature type with it.
Equip {2}

Naru Meha, Master Wizard

Flash
When Naru Meha, Master Wizard enters the battlefield, copy target instant or sorcery spell you control. You may choose new targets for the copy.
Other Wizards you control get +1/+1.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters the battlefield with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

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.)

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Nyx Lotus

Nyx Lotus enters the battlefield tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Seafloor Oracle

Whenever a Merfolk you control deals combat damage to a player, draw a card.

Loxodon Warhammer

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

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Arcane Adaptation

As Arcane Adaptation enters the battlefield, choose a creature type.
Creatures you control are the chosen type in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

Winged Sliver

Stubborn Denial

Counter target noncreature spell unless its controller pays {1}.
Ferocious — If you control a creature with power 4 or greater, counter that spell instead.

Betrayal

Enchant creature an opponent controls
Whenever enchanted creature becomes tapped, you draw a card.

Peer Pressure

Choose a creature type. If you control more creatures of that type than each other player, you gain control of all creatures of that type. (This effect lasts indefinitely.)

Reliquary Tower

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

Stolen Identity

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.)

Mistform Ultimus

Mistform Ultimus is every creature type (even if this card isn't on the battlefield).

Manifold Insights

Reveal the top ten cards of your library. Starting with the next opponent in turn order, each opponent chooses a different nonland card from among them. Put the chosen cards into your hand and the rest on the bottom of your library in a random order.

Snow-Covered Island

Arch of Orazca

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
{T}: Add {C}.
{5}, {T}: Draw a card. Activate only if you have the city's blessing.

Whelming Wave

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