Mist-Cloaked Herald

Siren Stormtamer

Flying
{U}, Sacrifice this creature: Counter target spell or ability that targets you or a creature you control.

Dive Down

Target creature you control gets +0/+3 and gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Entrancing Melody

Gain control of target creature with mana value X.

Diamond Mare

As this creature enters, choose a color.
Whenever you cast a spell of the chosen color, you gain 1 life.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Pteramander

Flying
{7}{U}: Adapt 4. This ability costs {1} less to activate for each instant and sorcery card in your graveyard. (If this creature has no +1/+1 counters on it, put four +1/+1 counters on it.)

Island

Negate

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Sleep

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

Exclusion Mage

When this creature enters, return target creature an opponent controls to its owner's hand.

Jace, Cunning Castaway

+1: Whenever one or more creatures you control deal combat damage to a player this turn, draw a card, then discard a card.
−2: Create a 2/2 blue Illusion creature token with "When this token becomes the target of a spell, sacrifice it."
−5: Create two tokens that are copies of Jace, except they're not legendary.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Essence Capture

Counter target creature spell. Put a +1/+1 counter on up to one target creature you control.

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice this Aura.

Merfolk Trickster

Flash
When this creature enters, tap target creature an opponent controls. It loses all abilities until end of turn.

Blink of an Eye

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Return target nonland permanent to its owner's hand. If this spell was kicked, draw a card.

Tempest Djinn

Flying
This creature gets +1/+0 for each basic Island you control.

Wizard's Retort

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