msem-instigator

Whenever another creature with power 4 or greater you control attacks, Ruthless Brawler deals 1 damage to defending player.

(Transform this if it's not attached to a creature. Pay {B} as a sorcery to unattach it.)
Enchant creature you control
Herald of Death's rider gets +1/+1.
Sacrifice a creature: Herald of Death's rider gets +2/+2 until end of turn.

Destroy target artifact. Vanquish the Obsolete deals 1 damage to each creature that artifact's controller controls.

{X}{W}{W}: Prevent the next X damage that would be dealt to target creature you control this turn. Whenever damage is prevented this way, you gain that much life.

Flash
When Turned by Fear enters, return up to one target creature to its owner's hand.
At the beginning of combat on your turn, up to one target creature gains menace until end of turn.

Flying
Revive {4}{B}{B} ({4}{B}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Target creature gets +2/+2 and gains indestructible until end of turn.

Whenever Herald of Purity is dealt damage, it deals that much damage to any target.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Up to two target lands you control become 1/1 black Bear creatures with deathtouch. They're still lands. (Then exile this card. You may cast the creature later from exile.)

Haste, prowess
Wanderlust — When Spitfireling enters, if you control four or more differently named lands, create two 1/1 red Elemental creature tokens with prowess and haste.

Changeling (This card is every creature type.)
As Kalyn, Wildkin Envoy enters, choose up to three non-Human creature types.
Other creatures you control with one or more of the chosen types get +1/+1.
{2}, {T}: Create a 1/1 colorless Shapeshifter creature token with changeling. Activate only outside of combat.

First strike, haste
Other creatures you control with flash or haste have first strike.

Cycling {2} ({2}, Discard this card: Draw a card.)

Whenever Krallenhorde Instigator deals combat damage to a player, create a 2/2 green Wolf creature token.
At the beginning of your end step, if Krallenhorde Instigator didn't attack this turn, transform it.

Enchant land you don't control
Whenever enchanted land becomes tapped, you may draw a card.

Voracious 2 (As this enters, you may sacrifice up to two artifacts and/or creatures. This creature enters with that many +1/+1 counters on it.)

Mill five cards, then return up to one permanent card from your graveyard to your hand.

Hexproof
At the beginning of your upkeep, put a card from your hand on top of your library. You may shuffle.
{1}: Look at the top three cards of your library, then put them back in any order.
{2}{U}: Draw a card.

Return up to one target creature card from a graveyard to the battlefield under your control.
Coalesce {9}{B} (You may cast this from your graveyard for {9}{B}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Indestructible

You may reveal a creature card from your hand. Return each creature with power less than the greatest power among creatures you control and creature cards revealed this way to their owners' hands .

All creatures get -2/-2 until end of turn.
Metamorph {1}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

When Parish Slayer enters, create a Weapon token. When you do, attach it to target creature you control. (A Weapon token is an Equipment artifact with “Equipped creature gets +1/+1” and equip {2}.)
{R}: Parish Slayer gains menace until end of turn.

When Silver Gardener enters, create a 1/1 green Saproling creature token.
Unveil {2}{G}{W} ({2}{G}{W}: Transform this. Unveil only as a sorcery.)

Flying
Morph {2}{W}{W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When you turn Wardwing Seraph face up, untap it.

Flying
When Carrion Drake enters, you may exile a creature card from your graveyard. If you do, draw a card.