msem-instigator

Lifelink
If a source would deal damage to a player, you may prevent X of that damage, where X is the number of +1/+1 counters on Mending Caretaker.

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Flying, vigilance

Flying, vigilance
Prevent all damage Merciful Yuroda would deal to creatures.

Merciless Champion can't block unless you control another Knight or Soldier.

Whenever Merciless Shieldbreaker enters or attacks, target opponent puts three rust counters on a permanent they control with no rust counters on it. That permanent gains “At the beginning of your upkeep, remove a rust counter from this permanent. Then if there are no rust counters on this permanent, sacrifice it and it deals 4 damage to you.”

This spell can't be countered.
Whenever Meren, Bane of the Cairns attacks, exile target creature card from your graveyard. You may cast that card for as long as it remains exiled by sacrificing a creature in addition to paying its other costs.

Whenever Merfolk Visionary or another Merfolk creature you control enters, scry 2. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Skip your draw step.
At the beginning of your upkeep, shuffle your hand and graveyard into your library, then draw three cards.
You can't cast more than one spell each turn.

Improve {1}{G/U} ({1}{G/U}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
You may play an additional land on each of your turns.
Wanderlust — At the beginning of your end step, if you control four or more differently named lands, you may draw a card.

When Meteor Harbinger enters, choose one —
• Meteor Harbinger deals 2 damage to each creature.
• Each player sacrifices two lands.
• Meteor Harbinger deals 2 damage to each of two target players or planeswalkers.

Flash

You may exert Migrating Herd as it attacks. When you do, sacrifice a land and draw a card. (An exerted creature won't untap during your next untap step.)

Lifelink
When Milunda, Prairie Prince enters, each opponent loses life equal to the number of storied permanents you control and you gain that much life. (Enchantments and legendary permanents are storied.)

Mindhunter Grizzly can't attack or block unless you scried this turn.
{5}{U}: Scry 1.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Mindscreech Drake deals combat damage to a player, that player mills three cards.

Whenever another nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of it, except it has base power and toughness 1/1. If that creature had power 4 or greater, create two of those tokens instead.

Heroic — Whenever you cast a spell that targets Mira and Kalisti of Akros, copy that spell. You may choose new targets for the copy. (The copy isn't cast. A copy of an Aura spell becomes a token.)

Flying
Whenever you cast an instant or sorcery spell, put a +1/+1 counter on Mirrorfuse Angel, then copy that spell for each +1/+1 counter on Mirrorfuse Angel. You may choose new targets for the copies.

Whenever a player casts an instant or sorcery spell that targets only one target or activates an ability that targets only one target, copy that spell or ability for each other target it could target. Each copy targets a different one of those targets. (A spell or ability can't target itself.)

Create a 1/1 blue Illusion creature token with “This gets +1/+1 for each other Illusion you control.”
Coalesce {6}{B} (You may cast this from your graveyard for {6}{B}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Misery Keeps Company is an Illusion in addition to its other types while it's a creature.

Flash (You may cast this spell any time you could cast an instant.)
When Mist Lurker enters, tap all creatures you don't control.

{1}{R}, Discard a card: Draw a card. Mist-Valley Minotaurs gets +2/+0 until end of turn.

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

Defender
When Mnemonic Wall enters, you may return target instant or sorcery card from your graveyard to your hand.