msem-instigator

Target creature gets +5/+5 until end of turn.
Fabled {4}{G} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

At the beginning of each player's end step, that player sacrifices a permanent.

Whenever an opponent casts a spell, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Spells your opponents cast cost an additional 2 life to cast until your next turn.

When Demented Brainiac enters and at the beginning of your upkeep, each opponent mills two cards.
{U}, Sacrifice Demented Brainiac: Exile each opponent's graveyard. Until end of turn, you may cast instant and sorcery spells exiled this way, and you may spend mana as though it were mana of any color to cast them.

Trample
At the beginning of your upkeep, sacrifice another creature. If you do, put X +1/+1 counters on Demented Host, where X is that creature's power.

Target player discards two cards.
Cycling {2}{B} ({2}{B}, Discard this card: Draw a card.)
When you cycle Dementia's Clutch, target player discards a card.

Destroy target artifact or land.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
When Demolitionist Deviser dies, it deals damage equal to its power to any target.

This spell costs {2} less to cast for each creature that died this turn.
Flying, trample

{1}{B}, Sacrifice another creature: Draw a card and 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.”)
{2}{B}, Sacrifice three Idols: Return Demon of Hubris from your graveyard to the battlefield. Activate only as a sorcery.

At the beginning of your end step, if you've sacrificed three or more permanents this turn, return Demon of Necessary Evil from your graveyard to the battlefield.

Whenever a player searches their library, that player can't untap more than two permanents during their next untap step.

Create a 4/4 black Demon creature token with flying. You lose 3 life for each Demon you control.
Tether (Then if you cast this from your hand, you may exile it tethered to a creature you control. When it dies, you may cast this from exile without paying its mana cost.)

When Demonqueller Mage enters, gain control of target creature with power 2 or less until Demonqueller Mage leaves the battlefield.

Submerge target artifact or enchantment. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Tap up to two target creatures.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle Denied Attempt, you may tap target creature.

Denouement deals damage to each creature and each planeswalker equal to the number of enchantments you control.

Counter target spell unless its controller pays {X}. If they do, you draw half X cards, rounded down.

As an additional cost to cast this spell, pay 1 life.
Departed Evangel can't block.
You may cast Departed Evangel from your graveyard if a creature died this turn.

Create three 1/1 colorless Servo artifact creature tokens.

Menace
When Depraved Archknight enters, each opponent may pay 7 life. For each player that doesn't, you draw seven cards.

{T}, Exile a card from your graveyard: Add {B}.

Flying
When Depraved Imp enters, if you control a legendary creature, put two +1/+1 counters on Depraved Imp.

Whenever a source you control deals damage to a creature or planeswalker an opponent controls, exile that creature or planeswalker.

First strike
Whenever Deprived Div deals combat damage to an opponent, end the turn. (Creatures without first strike won't deal damage this turn.)