msem-instigator

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.

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.

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.

Prowess
Whenever Knight-Academic attacks, scry 1.

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.

Flying
Whenever you cast a spell, exile the top card of your library.
At the beginning of your end step, put a card exiled with Korephyr, Riddle Sage into its owner's hand. Put each other card exiled with Korephyr on the bottom of its owner's library in a random order.
{3}{U/B}: Scry 2.

Whenever a creature token you control deals combat damage to an opponent, it deals that much damage to each other opponent.
At the beginning of combat on your turn, you may sacrifice another creature. If you do, create a 2/2 red, white, and black Knight creature token with haste.

Attacking creatures get +2/+0 until end of turn. If you control a legendary creature, those creatures also gain first strike until end of turn.

Return target card from your graveyard to your hand.

Lightning Ripple deals 4 damage divided as you choose among any number of target creatures and/or planeswalkers.

Flying, trample
When Lord of Sacrilege enters, each opponent loses 3 life, discards a card, then sacrifices a nonland permanent. If you control three or more Demons and/or Warlocks, instead each opponent loses 6 life, discards two cards, then sacrifices two nonland permanents.

Instant, sorcery, and legendary spells you cast cost {1} less to cast.

At the beginning of your end step, any number of target players mill three cards.
{5}{U/B}, {T}: You may cast target instant or sorcery card from an opponent's graveyard without paying its mana cost. Activate only as a sorcery.