msem-instigator

When Drift Tracer enters, search your library for a basic land card that shares a type with a basic land you control and put it onto the battlefield tapped, then shuffle.

When Drifting Warden enters, exile another target creature until Drifting Warden leaves the battlefield.
{3}{W}: Exile Drifting Warden. Return it to the battlefield under its owner's control at the beginning of the end step.

When Driftpicker enters, you may return another non-Crab creature you control to its owner's hand. If you do, create two 1/1 white Bird creature tokens with flying.

Creatures you control get +1/+1 until end of turn. Merfolk you control get an additional +1/+1 until end of turn.

Each player mills five cards.
Coalesce {4}{U}{B} (You may cast this from your graveyard for {4}{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.)
Drink Thoughts Like Oil can't be blocked.

Whenever you cast a spell during an opponent's turn, creatures you control get +0/+1 until end of turn.

Gain control of target creature until end of turn. Untap it. It gets +2/+0 and gains haste until end of turn.

Enchant creature
Whenever enchanted creature becomes tapped, return it and Driven to Distraction to their owner's hands.

Menace, haste
Other Centaurs you control get +1/+0.

When Driver of Hordes enters, create a tapped 2/2 black Zombie creature token.
Unearth {3}{B} ({3}{B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the end step or if it would leave the battlefield. Unearth only as a sorcery.)

{2/G}, {T}: Put a +1/+1 counter on target creature you control.

When Drop Bear enters, return another target permanent that isn't a land an opponent controls or a card in a graveyard to its owner's hand.

As Drop of Envy enters, choose a nonland permanent card name.
All cards not on the battlefield, spells, and permanents with the chosen name are legendary.

This spell costs {X} less to cast, where X is the number of card types among cards in your graveyard.
Surveil 3, then you draw three cards. You lose 3 life.

Target player draws a card for each card in their graveyard.

Flying
Whenever you cast a spell during an opponent's turn, Drosera and Nerium deals 1 damage to each opponent.
As long as Drosera and Nerium is tapped, you may cast spells as though they had flash.

Flying
Whenever a creature you control dies, put a +1/+1 counter on Drove of the Lost.
{1}, Sacrifice a creature: Each opponent loses 1 life. Gain 1 life.

{T}, Sacrifice a creature or land: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.

Landfall — Whenever a land you control enters, target player loses 1 life and you gain 1 life.

Drown deals 2 damage to target creature. That creature can't block this turn.

This spell can't be countered.
Tap up to three target permanents.
Coalesce {9}{U}{U} (You may cast this from your graveyard for {9}{U}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Opponents can't untap more than two permanents during their untap steps while Drown Amidst the Cosmos is on the battlefield.

When Drown in Apathy enters, exile target creature until Drown in Apathy leaves the battlefield. If a permanent would be returned to the battlefield this way, put it in its owner's hand instead.

Target player reveals their hand. You choose a nonland card from it. That player discards that card, then mills four cards.

All creatures get -2/-2 until end of turn. Scry 1.

{U}, Sacrifice a creature: Discard a card, then draw a card.