msem-instigator

Whenever you cast a white spell, creatures you control get +1/+0 until end of turn.
Whenever you cast a blue spell, draw a card, then discard a card.

Reach
When Cordial Ticketmaster enters, put a +1/+1 counter on target creature.

Enchant opponent
Whenever enchanted opponent casts a spell, you may reveal cards from the top of your library until you reveal a nonland card that costs less. Exile that card, and put the rest on the bottom in a random order. You may play the exiled card until the end of your next turn.

When Core Paradigm enters, conjure five cards named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)
Up to three times each turn, you may cast a sorcery spell without paying its mana cost.

Flying
When Cormoran, Raven Monarch enters, you may put target creature card with mana value 3 or less from a graveyard onto the battlefield under your control.

[+2]: Put two +1/+1 counters or loyalty counters on up to one other target creature or planeswalker.
[0]: Cornrose, the Mighty deals 3 damage to target creature. That creature deals damage equal to its power to Cornrose.
[–2]: Until end of turn, target creature gets +X/+X and gains trample, where X is its power.

Whenever another enchantment you control enters, you may put a progress counter on Corporate War.
[progress 2-5] {W}{B}, Sacrifice a creature or enchantment: Destroy target creature or enchantment.
[progress 6+] Sacrifice a creature or enchantment: Destroy target permanent.
Sacrifice a creature or enchantment: Destroy target permanent.

Whenever another Zombie you control enters, you may pay {1}{B}. If you do, exile target creature card from a graveyard. You gain life equal to its toughness.

{T}, Remove a +1/+1 counter from a creature you control: You draw a card and you lose 1 life.

Defender
Whenever a land you control enters, you may exile target permanent card from your graveyard.
Sacrifice a land: Put a card exiled with Corpsebark into its owner's hand.

({T}: Add {B}.)
Corpsebed enters tapped.
When Corpsebed enters, exile up to two target cards from graveyards.

Deathtouch
When Corpsecaster Mage enters, if you cast it, target creature card in your graveyard gains arise until end of turn. Its arise cost is equal to its mana cost. (Exile that card from your graveyard and pay its arise cost: Create a token that's a copy of it except it's a black Zombie in addition to its other types, has no mana cost, and can't block. Arise only as a sorcery.)

Whenever another Zombie or Demon creature you control enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Menace
Whenever you cast an instant or sorcery spell, create a 2/2 black Zombie creature token. This ability triggers only once each turn.

Menace
Sacrifice another creature: Corpulent Gibberer deals 1 damage to any target.
Evoke {1}{R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

First strike, trample
{2}{R}, Sacrifice a land: Corrignos' Rage gets +3/+0 until end of turn.

At the beginning of your upkeep, choose one —
• You lose 1 life.
• You draw two cards and you lose 3 life.
• Search your library for a card, put it into your hand, then shuffle. You lose 5 life.

When Corrupt Warden enters, up to one target creature gets -X/-X until end of turn, where X is the number of card types among cards in your graveyard.

This spell costs {1} less to cast for each card type among cards in your graveyard.
Deathtouch

Flying
{1}{B}, {T}: Destroy target creature that was dealt damage this turn.

Rhapsody {5}{R}{R} (Pay {5}{R}{R} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
When Corrupted Guardian enters, it deals damage equal to its power to up to one target player or planeswalker.

(Transform this if it's not attached to a creature. Pay {3}{B} as a sorcery to unattach it.)
Enchant creature you control
Corrupted Mount's rider gets +5/+4 and can't block.

Whenever an opponent casts a spell, that player gets a poison counter unless they pay {1}.
As long as an opponent has five or more poison counters, Corrupted Soothsayer gets +2/+1 and has flying.

Enchant creature
Enchanted creature gets +3/-2.

Whenever you cast a white spell, target player loses 2 life and you gain 2 life.
Whenever you cast a green spell, put a +1/+1 counter on Corrupted Warlord.