msem-instigator

Haste
When Horse Thief enters, you may gain control of target creature or Steed until end of turn. It gains haste until end of turn. If it's a Steed, attach it to Horse Thief.

Put a +1/+1 counter on target creature you control. Then that creature fights target creature you don't control. (Each deals damage equal to its power to the other.)

Vigilance
Imisti's Commando can't be blocked by creatures with lesser power.
Whenever Imisti's Commando deals combat damage to a player, draw a card.

Each opponent sacrifices a creature or planeswalker. If you own a foretold card in exile, you gain 4 life.

Whenever Imisti, Elven Insurgent attacks, mill two cards. When you do, you may return target land card from your graveyard to your hand.
{X}{B}{G}: If Imisti has no +1/+1 counters on it, put X +1/+1 counters on Imisti. Activate only as a sorcery.

When Impervious Fortifications enters, you gain life equal to the number of creatures you control.
Creatures can't attack you or a planeswalker you control unless their controller pays {2} for each creature they control that's attacking you.

Enchant creature
You may cast this spell from your graveyard if it targets a legendary creature you control.
Enchanted creature gets +2/+2 and has haste.

{T}: Add {C}.
{5}, {T}: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

Whenever you cast an instant or sorcery spell, Infernal Immolator deals 2 damage to each opponent.

Improve {W} ({W}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Whenever one or more embattled creatures you control attack, create a 1/1 white Cleric creature token with lifelink. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Create two 1/1 green Elf creature tokens, then up to one target creature gets +X/+X until end of turn, where X is the number of creatures you control. (Targets are chosen before the tokens are created.)

Whenever a creature you control leaves the battlefield, if it had counters on it, you may put one of those counters on Ironpact Marauder.
{1}{B}, Remove two counters from Ironpact Marauder: You draw a card and you lose 1 life.

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)

Whenever you cast a creature or planeswalker spell, if mana produced by a nonland permanent was spent to cast it, it gains trample and haste until end of turn.
{T}: Add {R} or {G}.

{T}: Izahl, the Stormbringer deals 1 damage to any target.
Whenever you cast a noncreature spell, you may untap target creature you control.

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.

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. You gain 3 life.

Flash
Flying
Legendary creatures you control have flying.

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.

As an additional cost to cast this spell, return any number of creatures you control to their owner's hands. This spell costs {2} less to cast for each creature returned in this way.
Trample, ward {3}
Keepers of the Rundfora's power and toughness are each equal to twice the number of cards in your hand.

Lifelink
Creature and Aura cards with mana value 3 or less in your graveyard have revive {2}{W/B}. ({2}{W/B}, Exile that card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

When Kindled Vengeance enters, if you cast it, create seven 1/1 green Elf creature tokens.
Whenever you attack, Kindled Vengeance deals damage equal to the number of attacking creatures to target creature or planeswalker an opponent controls.

Improve {R/W} ({R/W}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Whenever an embattled creature you control attacks, you may exile the top card of your library. During any turn you attacked with an embattled creature, you may play that card. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Whenever Knight of the Cockatrice attacks, you may pay {1}{R}. When you do, target creature can't block this turn.

This spell costs {1} less to cast for each embattled creature you control. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)
Haste
Whenever Knights of the Burning Pyre attacks, it deals X damage to each opponent, where X is the number of embattled creatures you control.