msem-instigator

When Seafloor Casket enters the battlefield and when you sacrifice it, target player mills two cards.
{1}{U}, Sacrifice Seafloor Casket: Draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

{T}: Scry 1.

Choose one —
• Counter target spell unless its controller pays {4}.
• Tap up to two target creatures. They don't untap during their controller's next untap step.

Pressure—{2}{U}{U}, Discard your hand. (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Reveal the top seven cards of your library. Put any number of noncreature, nonland cards from among them into your hand and the rest into your graveyard.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
{3}{U}: Target creature gains slipstream until end of turn.

Counter target spell if you have more cards in your graveyard than that spell's controller.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
{4}{B}{B}, {T}, Sacrifice Abalone Abomination: Create an X/X black Horror creature token, where X is the number of cards in your graveyard.

{B}, {T}, Discard a card: Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Pressure {3}{B}{B} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Each player sacrifices a creature. Put a creature card from a graveyard onto the battlefield under your control.

Target creature gets -4/-4 until end of turn. If that creature would die this turn, exile it instead.
Cycling {2} ({2}, Discard this card: Draw a card.)

Pressure {B} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Search your library for a card, put it into your graveyard, then shuffle. You gain 2 life.

Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard. You lose 1 life.

You mill two cards, draw two cards, lose 2 life, and create two Treasure tokens. (They're artifacts with “{T}: Sacrifice this permanent: Add one mana of any color.”)

Pressure—{B}, Exile six cards from your graveyard. (You may cast this spell for its pressure cost if there are seven or more cards in your graveyard.)
Deathtouch
{B}, Exile six cards from your graveyard: Return Danithra Champion from your graveyard to the battlefield. Activate only during your turn.

{B}, Sacrifice another creature: Exile target card in an opponent's graveyard. You may cast that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell. Activate only as a sorcery.

{T}, Discard a card, Sacrifice Danithra Oracle: Target creature gets -3/-3 until end of turn. Activate only as a sorcery.

Dawson's Collector can't block.
Whenever Dawson's Collector attacks, you may sacrifice another creature. If you do, create a tapped Treasure token.
Whenever you sacrifice your third permanent each turn, each opponent sacrifices a creature or planeswalker.

When Dawson's Enforcer enters the battlefield, draw a card if you sacrificed a permanent or discarded a card this turn.

Dawson's Marauder can't block.
When Dawson's Marauder attacks, it can't be blocked this turn unless defending player sacrifices an artifact.

Destroy target creature that's not enchanted and isn't an enchantment.

When Depthlight Brute enters the battlefield, if you control three or more artifacts, each opponent loses 3 life and you gain 3 life.

Deathtouch
When Depthlight Salvager enters the battlefield, you may salvage a creature card with mana value 3 or less. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)

{T}, Sacrifice an artifact or creature: Each opponent loses 1 life and you gain 1 life.

Look at target player's hand. You choose a nonland card from it. That player discards that card.
Create a 1/1 blue Jellyfish enchantment creature token with slipstream. (It can't be blocked as long as only creatures with slipstream are attacking.)