msem-instigator

{1}{B}, Pay 2 life: Moonlight Butcher gains menace until end of turn.

When Ragantiar enters, mill five cards.
{3}{B}, Sacrifice a creature: Return target creature card with power X or less from your graveyard to the battlefield, where X is 1 plus the sacrificed creature's power.

When Artillery Mage enters, it deals 5 damage to target creature you don't control.
{5}{R}, {T}, Discard a card: Artillery Mage deals 5 damage to target creature you don't control.

Menace (This creature can't be blocked except by two or more creatures.)
Whenever a creature you control deals combat damage to a player, you may have Aspect of Rage deal 1 damage to any target.

Whenever IG-2 Disassembler enters or attacks, you may sacrifice an artifact. When you do, IG-2 Disassembler deals 2 damage to target player or planeswalker.

Menace
Whenever you sacrifice an artifact or creature, Lava Scutterer deals 2 damage to any target.

Vanishing 1 (This creature enters with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever a creature you control deals combat damage to a player, put a time counter on Lavacore Elemental.

Menace
Other attacking Hounds you control get +2/+0.

{2}{R}: Target creature can't block this turn.

Trample, haste
Whenever Sugon, Destruction's Fist deals combat damage to a player, return it to its owner's hand unless you have Sugon deal 5 damage to you.

Whenever Ancient Durumderm attacks, you may return another creature you control to its owner's hand. If you do, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Trample
Madness {2}{G} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Whenever Insatiable Abomination or another Horror you control enters, each player mills four cards.
Exile a creature card from your graveyard: Tap target Horror you control. It gains indestructible until end of turn.

Reach
Lupine Skygrazer enters with a +1/+1 counter on it if three or more colors of mana were spent to cast it.

When Wolfbriar Sapling enters, if you control seven or more lands, create a 2/2 green Wolf creature token.

Gain control of target creature until end of turn.
Coalesce {6}{U}{B} (You may cast this from your graveyard for {6}{U}{B}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
As long as Mortal Whims Falter is on the battlefield, you can't lose control of permanents.

When Savannah Huntsman enters, it deals X damage to target creature or planeswalker, where X is the number of counters among permanents you control.

Harmony — Draw a card, then discard a card.
Whenever Dramatic Artist attacks, harmonize. (Trigger up to one harmony of one permanent you control.)

When Varakna Wurm enters, it deals X damage to target creature an opponent controls, where X is the total number of creature cards you own in exile and in your graveyard.
Cycling {2} ({2}, Discard this card: Draw a card.)

Creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, Bellowing Thoctar gets +2/+2 until end of turn.

First strike, trample
Death knell — Return a permanent card with mana value less than X from your graveyard to the battlefield, where X is the mana value of the last creature that died this turn. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

Bogchomper Juggernaut attacks each combat if able.
Bogchomper Juggernaut can't be blocked by Fungus, Saprolings, Plants, or Insects.