msem-instigator

Poisonblade Trainee enters with a -1/-1 counter on it.

You may exert Heavenly Bull as it attacks. When you do, it gains indestructible until end of turn. (An exerted creature won't untap during your next untap step.)
{3}{G}{W}: Destroy all nonland permanents with mana value 3 or less. Activate only if Heavenly Bull is attacking and only once.

Flash
Flying
When Laughing Bird enters, you may return a creature you control to its owner's hand.

You may have Icefang Wurm assign its combat damage as though it weren't blocked.
{4}{G}{G}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)

You may cast Heralds of Shikai from your graveyard as long as a creature an opponent controls died this turn.

When Hila Okunos enters, look at the top six cards of your library. You may reveal an Aura or Aurashaper card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Whenever another nontoken Aura or Aurashaper you control enters, create a token that's a copy of it.

Creatures your opponents control get -4/-0 until end of turn. Scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

Whenever Aravant Smuggler deals combat damage to an opponent, if it's embattled, draw a card. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

When Gruff Smith enters, you may destroy target artifact. If you do, that artifact's controller creates a colorless Equipment artifact token with “Equipped creature gets +1/+1” and equip {1}.
Recite {1}{R} (You may cast this creature from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)

Enchant creature
When Knightly Valor enters, create a 2/2 white Knight creature token with vigilance. (Attacking doesn't cause it to tap.)
Enchanted creature gets +2/+2 and has vigilance.

(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.

Vigilance
{G}, {T}: Exile up to three target cards from graveyards. If two or more of those cards share a card type, create a 1/1 colorless Servo artifact creature token.

Whenever you cast an Azra spell, mill three cards.
Whenever you cast a Demon spell, you may return an Azra card with lesser mana value than that spell from your graveyard to the battlefield.

Wanderlust — This spell costs {2} less to cast as long as you control four or more differently named lands.
Crackle Across Kahembo deals X damage to target creature or planeswalker.

Prowess
When Maktali Visionary enters, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Flash
When Cranial Glass enters, exile target card from a graveyard.
{7}, {T}, Sacrifice Cranial Glass: Copy the exiled card. You may cast the copy without paying its mana cost. (A copy of a permanent spell becomes a token.)

Enchant creature
Enchanted creature gets +2/+0 and has first strike.
Mirage {R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

When Artian, Phyrexian Architect enters, search your library for a land card, put it onto the battlefield, then shuffle.
At the beginning of your upkeep, put a corruption counter on a land you control. Then create a 1/1 colorless Phyrexian artifact creature token for each land you control with a corruption counter on it.

Whenever one or more other creatures you control deal combat damage to an opponent, choose one —
• That player discards a card at random.
• That player sacrifices a creature with toughness 4 or less.

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle. Put a +1/+1 counter on each creature you control.

Scry 3, then reveal the top card of your library. If it's a creature card, Hunter's Instinct deals damage to target creature equal to the revealed card's power.
Ferocious — If the revealed card is a creature card with power 4 or greater, put it into your hand.

Whenever a player casts a spell, put a time counter on Chronovore Clock. Then if there are ten or more time counters on it, remove all time counters from it and end the turn.

Whenever Malignant Afflicted perseveres, destroy target creature an opponent controls that dealt damage this turn. (A creature perseveres when it survives damage.)

[+2]: Exile up to three target cards from graveyards.
[+1]: Create a 2/1 black Horse Zombie creature token with lifelink.
[0]: If Undue has six or more loyalty counters on him, each opponent returns a creature card of their choice from a graveyard to the battlefield under your control.

Flash
Enchant player
When Curse of Tempests enters, it deals 3 damage to target creature or planeswalker enchanted player controls.
Whenever enchanted player is attacked, you may draw a card. If you do, discard a card.