msem-instigator

Whenever Tide Crasher attacks, if you control another Merfolk, tap target creature defending player controls.

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

Choose target creature you control and target creature you don't control. Flip a coin. If the coin comes up heads, put one of those creatures on top of its owner's library. Otherwise, put both of them on top of their owners' libraries.

Each opponent sacrifices a creature or planeswalker.
Acquiesce (If you cast this spell from your hand, exile it as it resolves. When one or more creatures you control deal combat damage to an opponent, you may cast this card from exile without paying its mana cost.)

Vanishing 4 (This creature enters the battlefield with four time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Remove a time counter from Tideshift Elemental: You may tap or untap target creature.

Once each turn, when a creature you control becomes tapped, you may untap that creature and tap up to one target creature.

Kicker {X}{U} (You may pay an additional {X}{U} as you cast this spell.)
When Tidetwister Mage enters the battlefield, if it was kicked, return all other creatures with power X or less to their owners' hands.

Menace, haste
Whenever Tiger of the Drums attacks, choose one —
• Exile target opponent's graveyard.
• You draw a card and lose 1 life.
• Torment each opponent. (They lose 3 life unless they discard a card or sacrifice a nonland permanent.)

Flying (This creature can't be blocked except by creatures with flying or reach.)
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.)

Enchant creature
When Til Death enters the battlefield, exile target creature an opponent controls other than enchanted creature until Til Death leaves the battlefield.
Enchanted creature has defender.

Untap target land. Scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)
Fabled {3}{G}{G} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that land.)

Create X 0/1 green Plant creature tokens, then distribute X +1/+1 counters among any number of creatures you control.

Flying, prowess
Whenever you cast a noncreature spell, reveal the bottom two cards of your library. Target opponent chooses one of them. Put that card on the bottom of your library and the rest into your hand.

When Tiller's Adze enters the battlefield, draw a card.
Equipped creature gets +1/+1.
Equip {1}

Each opponent sacrifices an artifact or enchantment.
Showcase {2}{G}{G} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Take an extra turn after this one. Exile Time if it wasn't fused.
Fuse (You may cast one or both halves of this card from your hand.)

{16}, {T}: Time Cube gains “At the beginning of your end step, if it's not an extra turn, take three extra turns after this one” and loses this ability.

Put target nonland permanent into its owner's library second from the top.

Return target permanent to its owner's hand. If this spell wasn't cast from your hand, put that permanent on top of its owner's library instead.
Coalesce {9}{U} (You may cast this from your graveyard for its coalesce cost. If you do, put it onto the battlefield as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Choose target permanent. Take an extra turn after this one. During that turn's untap step, permanents other than the chosen permanent phase out until end of turn. Exile Time Stands Still.

Target creature you control gets +4/+4 until end of turn.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “III—You may cast a copy of this card from exile without paying its mana cost.”)

Take an extra turn after this one. Exile Time in a Bottle.
Augmented — If you've spent {W}{U}{B}{R}{G} to cast spells this turn, draw three cards.

Exile target creature, then return that card to the battlefield under its owners' control.

When Timecrafter Lafterii enters the battlefield, choose target permanent with one or more time counters on it, then put two time counters on it or remove two time counters from it.