msem-instigator

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.

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

You may look at the top card of your library any time.
Once during each of your turns, you may play a land from the top of your library as though you could play an additional land.
{3}{G}{G}: You may cast the top card of your library without paying its mana cost if it's a creature card. Activate only as a sorcery.

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.)

When Jobiah, Devoted Farmer enters, search your library for a land card, put it onto the battlefield tapped, then shuffle.
At the beginning of your upkeep, if you control six or more lands with different names, you may transform Jobiah.

Johanna, Skarvith Marshal has first strike as long as it's attacking.
Whenever you attack, you may pay {X}{R/W}{R/W}. When you do, put a +1/+1 counter on each of up to X target attacking creatures. Those creatures gain first strike until end of turn.

If another creature you control would die, exile it instead.
When John Furo, the Unfortunate dies, until your next end step, you may play cards exiled with John Furo.

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

Whenever Journeying Giftbearer or another nontoken creature you control enters, create a green and white Aura enchantment token named Wild Boon attached to that creature. The token has enchant creature and “Enchanted creature gets +1/+1.”

When Joyful Deviant enters or dies, it deals 1 damage to any target.

As Joyous Chromatelk enters, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.
{T}: Add one mana of the chosen color.

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.)

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.

Juvenile Boa gets +2/+0 as long as you control a legendary creature.

Flash
Flying

Engorge (As this enters, mill three cards, then exile a card from among the milled cards.)
Whenever an instant or sorcery card you own is exiled from anywhere, you gain 1 life.

Creature spells you cast with power 4 or greater cost {1} less to cast.

When Kalak Culler enters, each opponent loses life equal to the number of creatures you've sacrificed this turn.
Revive—{3}{B}, Sacrifice a creature. ({3}{B}, Sacrifice a creature, 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, haste
Ward—Pay 3 life.
The first Dragon spell you cast each turn costs {R}{R} less to cast. (This can reduce the amount of generic mana you pay.)

Prowess
You may activate inscribe abilities from your graveyard as though they were in your hand.

Rhapsody {5}{W}{W} (Pay {5}{W}{W} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
When Kan's Faithful enters, exile up to one target nonland permanent with mana value X or less until Kan's Faithful leaves the battlefield, where X is Kan's Faithful's power.

This spell can't be countered.
Trample
Whenever an opponent draws a card except the first one they draw in each of their draw steps, put a +1/+1 counter on Kareki Magehunter.

Vigilance
Revive {3}{G} ({3}{G}, 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.)

Vigilance
Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{2}{W}{W}: Creatures you control get +1/+1 until end of turn.