River Heralds' Boon

Put a +1/+1 counter on target creature and a +1/+1 counter on up to one target Merfolk.

Crown of Vigor

Enchant creature
Enchanted creature gets +1/+1.
Sacrifice this Aura: Enchanted creature and other creatures that share a creature type with it get +1/+1 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.

Lead the Stampede

Look at the top five cards of your library. You may reveal any number of creature cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in any order.

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Vodalian Mage

{U}, {T}: Counter target spell unless its controller pays {1}.

Mist-Cloaked Herald

Watertrap Weaver

When this creature enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Moonblade Shinobi

Ninjutsu {2}{U} ({2}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, create a 1/1 blue Illusion creature token with flying.

Jade Guardian

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
When this creature enters, put a +1/+1 counter on target Merfolk you control.

Tishana's Wayfinder

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.)

Vines of Vastwood

Kicker {G} (You may pay an additional {G} as you cast this spell.)
Target creature can't be the target of spells or abilities your opponents control this turn. If this spell was kicked, that creature gets +4/+4 until end of turn.

Triton Shorestalker

Jungleborn Pioneer

When this creature enters, create a 1/1 blue Merfolk creature token with hexproof. (It can't be the target of spells or abilities your opponents control.)

Crown of Ascension

Enchant creature
Enchanted creature has flying.
Sacrifice this Aura: Enchanted creature and other creatures that share a creature type with it gain flying until end of turn.

Forest

Island

Jade Bearer

When this creature enters, put a +1/+1 counter on another target Merfolk you control.

Mistblade Shinobi

Ninjutsu {U} ({U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, you may return target creature that player controls to its owner's hand.