msem-instigator

When Inner-Eye Obscurist enters, return each other creature that isn't in Inner-Eye Obscurist's pack to their owners' hand. (Two or more creatures you control with equal power are in a pack.)

Whenever Insatiable Abomination or another Horror you control enters, each player mills four cards.
Exile a creature card from your graveyard: Tap target Horror you control. It gains indestructible until end of turn.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{U}{R}: Target creature without prowess gains prowess until end of turn. Activate only if Intelligence is in your graveyard.

Trample
When Ironhide Hadhayosh dies, put two +1/+1 counters on target creature you control.

Trample
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Isolated Guardian. It loses this ability and gains “Whenever this attacks, put two +1/+1 counters on each of up to two target creatures.”

Wildcast — When Ivier, Soul of the Woods enters, return target monocolored creature card from your graveyard to your hand. If mana from a nonland source was spent to cast Ivier, return that card to the battlefield instead.

Menace
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Jaded Guardian. It loses this ability and gains “Whenever this creature attacks, defending player sacrifices two permanents.”

Once each turn, when Jeffery enters or you create an Aura token, you may create an Aura Role enchantment token named Lead Role attached to target creature you control. It's all colors and has enchant creature you control and “Enchanted creature has base power and toughness 5/5, is all creature types, and has flying, vigilance, trample, lifelink, and prowess.”
Whenever an enchanted creature you control attacks, draw a card.

Flying
Once during each of your turns, for each creature you control, you may activate one of that creature's activated abilities with {T} in its cost without paying {T} and as though that creature had haste.

This spell costs {1} less to cast for each spell you cast this turn.
When Jidai Serpent enters, draw two cards.

Menace
Vanguard — Whenever a creature you control attacks alone, it gets +1/+1 until end of turn for each creature card in your graveyard.

When this creature enters, put two -1/-1 counters on a creature you control.
When this creature dies, put a -1/-1 counter on up to one target creature for each -1/-1 counter on this creature.

Flying, trample
At the beginning of your upkeep, sacrifice a creature.
Revive {2}{B}{B} ({2}{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.)

Flying
Kai'Wej, the Desolate has indestructible as long as you control no other creatures.
{1}{B}{B}, Sacrifice two creatures: Return Kai'Wej from your graveyard to the battlefield tapped.

Reach
When Kindly Greatwood enters, you gain 5 life and draw a card.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{3}{B}{B}: Choose any number of other nontoken creatures you control. Whenever one of those creatures dies this turn, create a token that's a copy of that creature, except it has no mana cost.

Whenever Knotweald Ambassador becomes the target of a spell or ability an opponent controls, choose one —
• Knotweald Ambassador deals damage equal to its power to target creature or planeswalker that player controls.
• Draw a card.

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
At the beginning of combat on your turn, Knotwood Lumberer gains your choice of vigilance or trample until end of turn.

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.

Flying
When Krothuss, Abyssal Terror dies, return all creatures to their owners' hands except for Krakens, Leviathans, Octopuses, and Serpents.
Foreshadow {6}{U}{U} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

When Kula's Disciple dies, put it on the bottom of its owner's library.

Haste
LH-6 Brutality can't attack or block unless you have two or fewer cards in hand.
{T}: Each player discards a card. Activate only as a sorcery.

Flying
Other Dragons you control have haste.
{R}: Dragons you control get +1/+0 until end of turn.

Trample
Other creatures you control get +1/+1 and have trample.

Menace
Whenever you sacrifice an artifact or creature, Lava Scutterer deals 2 damage to any target.