msem-instigator

Search target opponent's library for a card and exile it, then do the same for their hand and graveyard. That player shuffles. You may cast spells exiled this way for as long as they remain exiled, and you may spend mana as though it were mana of any color to do so.

Flash
When Dehmi, Origin Seeker enters, counter target spell an opponent controls unless that spell's controller has you create X 1/1 red Elemental creature tokens, where X is that spell's mana value.

When Deliver from Dilapidation enters, you may sacrifice any number of enchantments. Whenever you sacrifice an enchantment this way, destroy target creature.
At the beginning of your upkeep, return target enchantment card with mana value 5 or less from your graveyard to the battlefield.

Creatures you control get +1/+1 for each noncreature spell you've cast this turn.
When Deliverance Branch enters, create three 1/1 white Cleric creature tokens with lifelink.

Repeat the following process X times. Reveal the top two cards of your library. Put one of them into your hand and the other into your graveyard.

At the beginning of your upkeep, choose a creature. Its controller may sacrifice it. If that player doesn't, you gain life equal to its power.

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.

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

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.

As Den of Vice enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}, {B}, or {R}.

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.

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.)

{2}{U}{B}: Return Depth Charger to its owner's hand. If you do, return target creature to its owner's hand. That player discards a card.

When Deputy Gibem enters, post a bounty on each creature and each planeswalker. (Put a bounty counter on those permanents. Each of them have “When this permanent dies, each opponent draws a card” as long as it has a bounty counter on it.)

Target player discards two cards.
Rerun (If you cast this from your hand, exile it as it resolves. Whenever a creature you control dies, you may cast this card from exile without paying its mana cost.)

Frenzy 3 (Whenever this creature attacks and isn't blocked, it gets +3/+0 until end of turn.)
Other red creatures you control have frenzy 2. (If a creature has multiple instances of frenzy, each triggers separately.)
Other creatures you control have frenzy 1.

{T}: Add one mana of any color.
When you tap Derelict Town for mana, return it to its owner's hand.

Flying
When Derevi's Adjutant enters, put a +1/+1 counter on each other creature you control.
Cycling {2} ({2}, Discard this card: Draw a card.)
When you cycle Derevi's Adjutant, exile it. You may cast it from exile for as long as it remains exiled.

This spell costs {1} less to cast for each card you've drawn this turn.
Return up to three target creatures with total mana value 5 or less from your graveyard to the battlefield.