msem-instigator

Haste (This creature can attack and {T} as soon as it comes under your control.)

First strike (This creature deals combat damage before creatures without first strike.)
Whenever a creature you control becomes blocked by a creature, Itava Scourge deals 1 damage to that creature's controller.

Menace (This creature can't be blocked except by two or more creatures.)
Itava Warshrieker attacks each combat if able.

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.

If an enchanted permanent you control would leave the battlefield, instead destroy one of the Auras attached to it, then that permanent phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Vigilance
{3}{W}, {T}: Tap target creature. This ability costs {3} less to activate as long as J-7 Freeze Frame is a creature.
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Vehicle becomes an artifact creature until end of turn.)

Art of war — At the beginning of your end step, if Jaakuna Betrayer dealt damage to an opponent this turn, you may discard a card. If you do, draw a card.

When Jaakuna Bloodsworn enters, any opponent may have it deal 3 damage to them. If a player does, sacrifice Jaakuna Bloodsworn.

Vigilance
Augmented — Whenever Jacque attacks, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, you may exile any number of target nonland permanents, then return them to the battlefield tapped under their owners' control.

When Jade Empire Cartographer enters, choose one —
• Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
• Put a +1/+1 counter on target creature you control.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{3}{G}, Sacrifice Jade Vault Reclaimer: Destroy target artifact or enchantment.

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.”

Activated abilities you activate cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.
Attain {5}{U} ({5}{U}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Jara Favored gets +2/+2 as long as you've lost life this turn.

Trample, haste
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)

Menace
Inspired — Whenever Jeering Kit becomes untapped, target Fox you control gets +1/+1 until end of turn.

Haste
When Jetskate enters, if you've drawn two or more cards this turn, it deals 2 damage to any target.
Cycling {R} ({R}, Discard this card: Draw a card.)

Vigilance
{1}{W}: Jhessian Cavalier gains lifelink until end of turn.

Other attacking Foxes you control get +1/+0.
{2}{R}, Sacrifice Jiu: Discard your hand, then draw a card for each tapped Fox you control.

Whenever one or more creatures deal combat damage to you, put a -1/-1 counter on one of them.
Attain {5}{W} ({5}{W}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Menace, lifelink
Whenever Jonah of the Spellbane deals combat damage to a player, destroy target creature or planeswalker, then scry 1.

Double strike, menace, trample
At the beginning of your end step, sacrifice Juddering Mishap unless you've cast a spell with no creature types this turn. (Noncreature spells have no creature types.)

Menace
Swampcycling {1}, forestcycling {1} ({1}, Discard this card: Search your libary for a Swamp or Forest card, reveal it, put it into your hand, then shuffle.)

{1}{R}: Exile the top card of your library. If it's a creature card, you may play it until the end of your next turn.
{4}{W}: Put two +1/+1 counters on target creature.

When Junktrawler enters, create a tapped colorless Powercell artifact token with “{T}: Add {C}.”
Tap another untapped artifact you control: Junktrawler gets +1/+1 until end of turn.