msem-instigator

Whenever Wild Bearmaster attacks, each other attacking creature you control gets +X/+X until end of turn, where X is Wild Bearmaster's power.

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Whenever Wild Lifescale attacks, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Whenever you cast a creature spell, if it has a creature type no creature you control has, upgrade Wild Outlander. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Vigilance
• Trample

Flying
{1}{W}{U}: Submerge another target creature. When An and En, Destined Souls leaves the battlefield, turn that creature face up. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Flash
You may cast Elemental spells as though they had flash.
Once each turn, when you cast an instant spell, you may put a +1/+1 counter on target Elemental you control.

Whenever Atieh's Destiny or another creature you control enters, you gain 1 life and scry 1.

When Blinding Fiddler enters, until your next turn, creatures can't attack you or a planeswalker you control unless their controller pays {2} for each of those creatures.
Unveil {3}{W}{U} ({3}{W}{U}: Transform this. Unveil only as a sorcery.)

Flash
Return another artifact, creature, or enchantment you control to its owner's hand: Caylin Whirlwind gets +3/+3 until end of turn. Activate only once each turn.

When Coralight Paladin enters, you may search your library for an artifact card, reveal it, then shuffle and put that card on top.
Concord — Whenever Coralight Paladin attacks, if there are four or more card types among permanents you control, Merfolk you control get +1/+1 until end of turn.

First strike
Noncreature spells cost {1} more to cast as long as their controller is horrific. (A player is horrific as long as they've sacrificed a permanent or discarded a card this turn.)

Whenever you scry, tap target creature an opponent controls.
{2}{W}{U}: Scry 1. You gain 1 life.

Whenever you scry, put a +1/+1 counter on Dunesea Cartographer for each card you looked at while scrying this way.
{3}{W}{U}: Scry 2.

Flying, vigilance
Embattled creatures you control have ward {1}. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)
Whenever one or more creatures you control deal combat damage to a player, put a +1/+1 counter on one of those creatures.

Gild-Cloak Strider can't be blocked by creatures with greater power.
{1}{W/U}: Return Gild-Cloak Strider to its owner's hand.

Flying
Unveil {3}{W}{U} ({3}{W}{U}: Transform this. Unveil only as a sorcery.)

Flying
Whenever a Harpy you control becomes the target of a spell, scry 1.

Flying

First mate—Each nonland card in your starting deck is an instant or has flash. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Flash
When Mable enters, you gain 2 life and draw a card.

You can't cast more than one spell each turn.
Whenever you cast a spell, draw a card.

When Persecution Official enters, choose a creature card name.
Cards with the chosen name can't be cast.

Whenever another creature you control enters, you may upgrade Relitian Renegade. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Ward {2}
• Flying
• Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)

Flying
When Rimecraft Owl enters, you may put an Aura card with mana value 3 or less from your hand or graveyard onto the battlefield attached to Rimecraft Owl or target creature an opponent controls that Aura could enchant.

Flying
When Shomi's Savior enters, scry 3, then you gain 3 life.
Whenever you scry, put a +1/+1 counter on Shomi's Savior.

First strike
Whenever Sighted-Caste Knight deals combat damage to a player, draw a card.

As Silent Hypnotist enters, choose a noncreature card name.
Spells with the chosen name can't be cast.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.