Merchant Ship can't attack unless defending player controls an Island.

Whenever Merchant Ship attacks and isn't blocked, you gain 2 life.

When you control no Islands, sacrifice Merchant Ship.

Afflict 2 (Whenever this creature becomes blocked, defending player loses 2 life.)

, Discard a card: Merciless Eternal gets +2/+2 until end of turn.

When Merciless Executioner enters, each player sacrifices a creature of their choice.

, Discard a card: Put a -1/-1 counter on target creature. That creature can't block this turn.

Exile target creature. Incubate 3. (Create an Incubator token with three +1/+1 counters on it and ": Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)

, : Draw two cards.

, , Discard a card: Mercurial Chemister deals damage to target creature equal to the discarded card's mana value.

Flying

Whenever Mercurial Kite deals combat damage to a creature, tap that creature. That creature doesn't untap during its controller's next untap step.

Mercurial Spelldancer can't be blocked.

Whenever you cast a noncreature spell, put an oil counter on Mercurial Spelldancer.

Whenever Mercurial Spelldancer deals combat damage to a player, you may remove two oil counters from it. If you do, when you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Target creature's controller sacrifices it, then creates X 1/1 green and white Elf Warrior creature tokens, where X is that creature's power.

Whenever another creature you control dies, you get an experience counter.

At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.

When Merfolk Branchwalker 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.)

: Merfolk Coralsmith gets +1/-1 until end of turn.

When Merfolk Coralsmith dies, scry 2.

: Draw a card, then discard a card.

Other Merfolk you control get +1/+1.

Flash (You may cast this spell any time you could cast an instant.)

When Merfolk Pupil enters, draw a card, then discard a card.

, Exile Merfolk Pupil from your graveyard: Draw a card, then discard a card.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

: Tap target creature without flying.

When Merfolk Seer dies, you may pay . If you do, draw a card.

Flying

Whenever Merfolk Skyscout attacks or blocks, untap target permanent.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Whenever Merfolk Spy deals combat damage to a player, that player reveals a card at random from their hand.

When Merfolk Traders enters, draw a card, then discard a card.

Flying

When Merfolk Wayfinder enters, reveal the top three cards of your library. Put all Island cards revealed this way into your hand and the rest on the bottom of your library in any order.

Tap an untapped nontoken artifact you control: Add .

Tap two untapped nontoken artifacts you control: Exile the top card of your library. You may play it this turn.

Reach

Domain — When Meria's Outrider enters, it deals damage to each opponent equal to the number of basic land types among lands you control.

: Target player exiles a card from their graveyard.

Whenever you cast a black spell, you may untap Merrow Bonegnawer.

, : Target creature gets -2/-0 until end of turn. ( is the untap symbol.)

: Target creature gains flying until end of turn.

Whenever you cast a blue spell, you may untap Merrow Levitator.

, : Merrow Wavebreakers gains flying until end of turn. ( is the untap symbol.)

When Merry Bards enters, you may pay . When you do, create a Young Hero Role token attached to target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature has "Whenever this creature attacks, if its toughness is 3 or less, put a +1/+1 counter on it.")

Partner with Pippin, Warden of Isengard (When this creature enters, target player may put Pippin into their hand from their library, then shuffle.)

Whenever one or more artifacts you control enter, create a 1/1 white Soldier creature token with lifelink. This ability triggers only once each turn.

Visit — Creatures you control with power 2 or less gain horsemanship until end of turn. (They can't be blocked except by creatures with horsemanship.)

Lights — 5, 6

Flying

When Mesa Cavalier enters, you gain 2 life.

Whenever you cast an enchantment spell, you may draw a card.

During turns other than yours, Mesa Lynx gets +0/+2.

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Counter target spell with mana value 3 or less. (Then exile this card. You may cast the creature later from exile.)

All Slivers have "When this permanent enters, you may fateseal 1." (To fateseal 1, its controller looks at the top card of an opponent's library, then they may put that card on the bottom of that library.)

When Mesmerizing Benthid enters, 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.

Flying

When Messenger Drake dies, draw a card.

Flying

Council's dilemma — When Messenger Jays enters, starting with you, each player votes for feather or quill. Put a +1/+1 counter on Messenger Jays for each feather vote and draw a card for each quill vote. For each card drawn this way, discard a card.

Cards in the winning deck(s) of the latest Mythic Championship cost more to cast.

Gain control of target artifact until end of turn. Untap that artifact. It gains haste until end of turn.

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for .)

Counter target spell unless its controller pays .

, : Regenerate target artifact.

When Metalspinner's Puzzleknot enters, you draw a card and you lose 1 life.

, Sacrifice Metalspinner's Puzzleknot: You draw a card and you lose 1 life.

: Reveal any number of artifact cards in your hand. Add for each card revealed this way.

Spree (Choose one or more additional costs.)

+ — Until end of turn, target creature becomes a white Rabbit with base power and toughness 0/1.

+ — Target player draws two cards.

Put target permanent an opponent controls on top of its owner's library. That opponent may put an artifact, creature, enchantment, or land card from their hand onto the battlefield.

Lifelink

When Metamorphosis Fanatic enters, return up to one target creature card from your graveyard to the battlefield with a lifelink counter on it.

Miracle (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Flying

: You may put a creature card with mana value X from your hand onto the battlefield. If you do, return Metathran Aerostat to its owner's hand.