msem-instigator

Pressure {1}{U} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Exile up to two target nonland permanents you control, then return them to the battlefield under their owner's control.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Whenever Happy Manta deals combat damage to a player, draw a card for each card type among spells you've cast this turn.

Pressure {1}{U}{U} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Draw three cards.

Draw cards equal to the number of cards in your hand, then discard three cards.
Cycling {U} ({U}, Discard this card: Draw a card.)

Pressure {X}{U}{U} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Look at the top card of your library. You may put that card into your graveyard.
Draw a card. If this spell was cast for its pressure cost, draw X cards instead.

Enchant creature
You control enchanted creature.
Enchanted creature gets +1/+1 and has slipstream. (This creature can't be blocked as long as only creatures with slipstream are attacking.)

Counter target creature spell. You may cast a copy of that spell. (You still pay its costs. The copy becomes a token.)

When Edina's Soulsinger enters, 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.)

Pressure {3}{U} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Return target creature to its owner's hand. If this spell was cast for its pressure cost, put that creature into its owner's library second from the top instead.

Deep-Sea Terror can't attack unless seven or more cards are in your graveyard.

Pressure {6}{U}{U} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Take an extra turn after this one. If this spell was cast for its pressure cost, during that turn, whenever you tap an Island for mana, add an additional {U}.
Exile Cuxuri Rift.

Pressure {1}{U} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
When Cuxuri Harbinger enters, draw a card.

Pressure {U}{U} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Counter target spell.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Cycling {U} ({U}, Discard this card: Draw a card.)

Enchant creature
Concord — When Coral Guidance enters, if there are four or more card types among permanents you control, draw a card.
Enchanted creature doesn't untap during its controller's untap step.

Concord — When Coral Bruiser enters, if there are four or more card types among permanents you control, put target creature you don't control into its owner's library third from the top.

When Bubblespout Sentry enters, look at the top card of your library. You may put it into your graveyard.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Concord — As long as there are four or more card types among permanents you control, Bubbledome Waveblade gets +1/+1.

Whenever you cast an enchantment, instant, or sorcery spell, 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.)

Whenever you draw a card, you may have target player mill two cards.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Sacrifice Bonetooth Darter: Counter target instant, planeswalker, or sorcery spell unless its controller pays {1}.

When Trident of Benediction enters, create two 1/1 white Merfolk creature tokens.
Equipped creature has vigilance and “Whenever this creature attacks or blocks, creatures you control get +1/+1 until end of turn.”
Equip {2}

As long as you control three or more artifacts, Treasury Master gets +2/+0 and has slipstream. (This creature can't be blocked as long as only creatures with slipstream are attacking.)

For each player, you choose from among the permanents that player controls an artifact, a creature, an enchantment, and a planeswalker. Then each player sacrifices all other nonland permanents they control.

Permanents you control gain indestructible until end of turn. Untap each creature you control.
Cycling {W} ({W}, Discard this card: Draw a card.)