msem-instigator

Enchant opponent
At the beginning of enchanted player's upkeep, they mill two cards.
{U}, Sacrifice Strange Tides: Shuffle up to four target cards from your graveyard into your library.

Concord — At the beginning of combat on your turn, if there are four or more card types among permanents you control, Sturdyshell Hammerclaw gets +2/+1 and gains trample until end of turn.

When Stygian Leviathan enters, target opponent loses life equal to the number of Curses attached to them and you gain that much life.

This spell costs {1} less to cast for each Horror you control.
Exile up to one target non-Horror creature.
Coalesce {7}{W} (You may cast this from your graveyard for {7}{W}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

First strike, vigilance
When Subnautical Legionnaire enters, choose artifact, enchantment, or Merfolk. Exile target nonland permanent you don't control until you control no permanents of the chosen type.

Tap up to two target creatures. Those creatures don't untap during their controllers' next untap steps. Scry 1.

At the beginning of your upkeep, Suitor of the Sea deals 1 damage to each player.

{2}: Other creatures you control get +1/+0 until end of turn.
Whenever Sun-Crowned Flagship attacks, each attacking creature you control gains trample until end of turn.
Crew 7 (Tap any number of creatures you control with total power 7 or greater: This Vehicle becomes an artifact creature until end of turn.)

Pressure {3}{B}{G} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
When Sunken-Eye Angler enters, mill three cards. Then if it was cast for its pressure cost, you may return a creature card from your graveyard to the battlefield.

Haste
At the beginning of combat on your turn, target creature or Vehicle you control gets +2/+0 until end of turn.

Flying
When Swooping Razorbeak enters, you may return another permanent you control to its owner's hand.

First mate—Your starting deck contains no more than eight cards of each nonland card type. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Lifelink
At the beginning of your upkeep, you may pay 3 life. If you do, exile another target nonland permanent until Tabia leaves the battlefield. If you control another permanent that shares a card type with it, exile it instead.

Search your library for a card, put it into your hand, shuffle, then add three mana in any combination of colors.
{1}, Discard Tahli's Council: Add one mana of any color. Scry 1.

[+1]: Scry 1. Untap up to one target creature.
[–2]: Mill a card for each card type among permanents you control, then you may return a land card and/or a nonland card milled this way to their owner's hand.
[–6]: Until end of turn, you may cast spells from your hand and graveyard without paying their mana costs. If a card would be put into your graveyard from anywhere this turn, exile it instead.

{1}, {T}: Tap target nonartifact creature.

This spell costs {2} more to cast for each target beyond the first.
Choose one or more —
• Exile target enchantment.
• Target player creates two tapped 1/1 white Soldier creature tokens.
• Taranika's Endeavor deals damage equal to the number of creatures you control to target creature or planeswalker.

You may play Tectonic Chateau from your graveyard as long as seven or more cards are in your graveyard.
Tectonic Chateau enters tapped.
{T}: Add {R} or {W}.
Cycling {1}{R}{W} ({1}{R}{W}, Discard this card: Draw a card.)

Discard a card: Tender Warden gets +2/+2 until end of turn. Activate only during your turn.

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.

Choose one —
• Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.
• Until end of turn, if a creature would enter and it wasn't cast, exile it instead.
Flashback {1}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Enchant opponent
Whenever enchanted player draws a card or casts a spell, put a foreshadow counter on Thalassophobia.
Remove eight foreshadow counters from Thalassophobia and sacrifice it: Create an 8/8 blue Kraken creature token.

Target player discards a card and gets a poison counter.
Coalesce {4}{B}{B} (You may cast this from your graveyard for {4}{B}{B}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

The Mythical Zhiwu enters with four +1/+1 counters on it.
{1}, Remove a +1/+1 counter from a creature you control: Target creature gets -1/-1 until end of turn. Activate only as a sorcery.
{1}, Remove a +1/+1 counter from a creature you control: Each opponent loses 1 life and you gain 1 life.

For each legendary permanent you control, this spell costs one mana of one of that permanent's colors less to cast. This effect reduces only the amount of colored mana you pay.
For each color, create a token that's a copy of a different legendary permanent you control of that color, except the token isn't legendary.
Exile The Tale of Kings.

Whenever The Winged Steed attacks, create a 4/4 red Dragon creature token with flying that's tapped and attacking. Exile that token at end of combat.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)