msem-instigator

Whenever a creature attacks one of your opponents, that player loses 1 life.

Lifelink
At the beginning of your upkeep, Osgaerith Desecrator deals 1 damage to up to one target creature.

Once during each of your turns, you may cast a legendary creature or planeswalker spell from your graveyard.
Sacrifice Pallid Herald: Exile up to three target cards from graveyards.

Deathtouch
When Pestilent Scavenger enters, you may mill three cards.

Deathtouch, lifelink
Improve {1}{W/B} ({1}{W/B}: 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.)
{4}: Target creature gains deathtouch and lifelink until end of turn. Activate only during a player's first main phase.

When Poisoned Shiv enters, destroy target creature or planeswalker.
Equipped creature gets +2/+0 and has deathtouch.
Equip {2}

Menace
Regal Dragoon gets +1/+1 as long as you control a legendary creature.

Flying
Rezzal, the Loamfeaster gets +1/+1 for each nonland card exiled with it.
You may play lands exiled with Rezzal.
{1}{B/G}: Exile target card from an opponent's graveyard. Activate only outside of combat.

When Ryleth, Vengeful Shadow enters, create two 1/1 green Elf creature tokens.
Whenever you attack, you may pay {1}{B/G}. When you do, return target creature card with mana value less than or equal to the number of attacking creature tokens you control from your graveyard to the battlefield tapped and attacking.

Flying
Improve—{1}{B/R}, Sacrifice a creature. ({1}{B/R}, Sacrifice a creature: 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 another creature you control dies, each opponent loses 1 life and you gain 1 life. If that creature was sacrificed, instead each opponent loses 2 life and you gain 2 life.

When Scion of Sarrithaz enters, create a 2/2 black Zombie creature token.
{2}{B}, Sacrifice a creature: Draw a card.

At the beginning of your upkeep, you lose 1 life and create a 1/1 white Soldier creature token with melee. (Whenever that creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)

Menace, lifelink
Whenever a creature enters under an opponent's control, you may have that player lose 1 life.

Target creature gets -3/-3 until end of turn. If you control a legendary creature, instead destroy that creature.

{1}, Sacrifice a creature: Each opponent loses 1 life and you gain 1 life.

All creatures get -2/-2 until end of turn. At the beginning of the next end step, if three or more creatures died this turn, create two tapped Treasure tokens.

Whenever you cast a noncreature spell, torment each opponent. (They lose 3 life unless they discard a card or sacrifice a nonland permanent.)
{3}{U/B}{U/B}: Draw a card for each opponent with ten or more cards in their graveyard. You lose that much life.

Flying
Once each turn, when a creature an opponent controls dies, you may create a Treasure token.
{3}{B/R}{B/R}: Search target opponent's library for a card and exile it face down. Then that player shuffles. You may look at and play that card for as long as it remains exiled. Activate only once each turn and only as a sorcery.

Menace, haste
As long as Arleigh, Spellblade Prodigy is tapped, the first spell you cast during each other player's turn costs {U/R} less to cast. This effect reduces only the amount of colored mana you pay. (For example, if you cast a spell with mana cost {1}{R}, it costs {1} to cast.)

Prowess
Whenever Balefire Conjurer attacks, you may pay {1}{R}. If you do, exile the top card of your library. You may play that card until the end of your next turn.

Improve {1}{R} ({1}{R}: 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.)
As long as Bloodbelly Glutton is embattled, it has first strike, menace, and haste. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Burning Grasp deals 3 damage divided as you choose among one or two targets.
Draw a card.

Cleave deals 1 damage to each opponent and 1 damage to each creature and planeswalker your opponents control.

Haste
{T}: Dragonfire Sniper deals 1 damage to target creature or planeswalker and 1 damage to that permanent's controller.

When Dragonheart Seer dies, you may exile it. If you do, return up to two target instant and/or sorcery cards from your graveyard to your hand.