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

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

If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on that creature instead.

Whenever another Merfolk you control enters, put a +1/+1 counter on target Merfolk you control.

Experiment Kraj has all activated abilities of each other creature with a +1/+1 counter on it. {T}: Put a +1/+1 counter on target creature.

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

{1}{G}{U}: Put a +1/+1 counter on target creature you control. Whenever one or more +1/+1 counters are put on a creature you control, put that many growth counters on this enchantment. At the beginning of your upkeep, if this enchantment has twenty or more growth counters on it, you win the game.

When this creature enters, create a Map token. (It's an artifact with "{1}, {T}, Sacrifice this token: Target creature you control explores. Activate only as a sorcery.") If a creature you control would explore, instead it explores, then it explores again.

{G}{U}, {T}: Double the number of each kind of counter on target artifact, creature, or land.

Whenever a creature you control explores, put a +1/+1 counter on this creature and you gain 3 life.

You may play an additional land on each of your turns. Landfall — Whenever a land you control enters, you may draw a card.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) Whenever this creature deals combat damage to a player, you may draw that many cards.

You may look at the top card of your library any time. You may cast Merfolk spells from the top of your library. Whenever you cast a Merfolk spell, you may pay {1}. If you do, create a 1/1 blue Merfolk creature token.

When Ezuri enters, you may pay {3}. If you do, proliferate twice. Whenever you proliferate, draw a card.

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.) Spells you cast with mana value 6 or greater have cascade.

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

When this creature enters, it explores, then it explores again. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard. Then repeat this process.)

When Kiora enters, draw two cards, then discard two cards. Threshold — Whenever Kiora attacks, if there are seven or more cards in your graveyard, you may create Scion of the Deep, a legendary 8/8 blue Octopus creature token.

Tap another untapped Merfolk you control: Kumena 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.

When this creature enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Whenever a creature you control enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the creature, then put the card back or put it into your graveyard.)

Prime Speaker Zegana enters with X +1/+1 counters on it, where X is the greatest power among other creatures you control. When Prime Speaker Zegana enters, draw cards equal to its power.

Changeling (This card is every creature type.) As this creature enters, choose a creature type. You may look at the top card of your library any time. You may cast creature spells of the chosen type from the top of your library.

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

Svyelun 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}.)

Landfall — Whenever a land you control enters, you gain 1 life and draw a card.

Tishana's power and toughness are each equal to the number of cards in your hand. You have no maximum hand size. When Tishana enters, draw a card for each creature you control.

Creatures you control with +1/+1 counters on them can't be blocked.

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

({T}: Add {G}.)

This land enters tapped unless you control a Forest or an Island. {T}: Add {G} or {U}.

({T}: Add {U}.)

This land enters 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.)

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

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.

Proliferate, then choose any number of permanents you control that had a counter put on them this way. Those permanents phase out. (To proliferate, choose any number of permanents and/or players, then give each another counter of each kind already there. Treat phased-out permanents and anything attached to them as though they don't exist until their controller's next turn.)

Flash When this creature enters, put a shield counter on another target creature you control. (If it would be dealt damage or destroyed, remove a shield counter from it instead.) You may cast Merfolk spells as though they had flash.

Whenever an opponent plays a land, you may put a land card from your hand onto the battlefield.

Draw a card. You may put a land card from your hand onto the battlefield.

{T}: Untap another target permanent.

Indestructible As long as your devotion to green and blue is less than seven, Kruphix isn't a creature. You have no maximum hand size. If you would lose unspent mana, that mana becomes colorless instead.

Whenever a creature you control explores a land card, you may put a land card from your hand onto the battlefield tapped. Whenever a creature you control explores a nonland card, put a +1/+1 counter on Nicanzil.

+2: Scry 2. 0: Look at the top card of your library. If it's a land card or a creature card with mana value less than or equal to the number of loyalty counters on Nissa, you may put that card onto the battlefield. −6: Untap up to two target lands you control. They become 5/5 Elemental creatures with flying and haste until end of turn. They're still lands.

{T}: Add {C}{C}.

Descend 8 — When you cast this spell, if there are eight or more permanent cards in your graveyard, copy this spell twice. You may choose new targets for the copies. Return target permanent card from your graveyard to your hand. Exile Bygone Marvels.

Counter target spell.

Kicker {X}. X can't be 0. (You may pay an additional {X} as you cast this spell.) Flying When this creature enters, if it was kicked, gain control of target artifact with mana value X or less. If that artifact is an Equipment, attach it to this creature.

Flash When this creature enters, counter up to one target activated or triggered ability. If an ability of an artifact, creature, or planeswalker is countered this way, that permanent loses all abilities for as long as this creature remains on the battlefield. (Mana abilities can't be targeted.)

Whenever one or more nontoken Merfolk you control become tapped, create a 1/1 blue Merfolk creature token with hexproof.

Other green creatures you control get +1/+1. Other blue creatures you control get +1/+1. Untap all green and/or blue creatures you control during each other player's untap step.