msem-instigator

When Benthic Tidebreaker enters, reveal the top card of each player's library and exile one of those cards. You may play that card for as long as it remains exiled, and you may spend blue mana as though it were mana of any color to cast it.
Evoke {1}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Target opponent may have Desperate Contrition deal 4 damage to them. If that player doesn't, you draw three cards.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

Whenever a source you control deals damage to an opponent this turn, exile the top card of your library. You may play it this turn.

Flash
Flying

Whenever you cast a spell, if it shared a color with the last spell you cast this turn, put two +1/+1 counters on Defected Android.

Counter target planeswalker spell.
Draw a card.

Whenever you cast a noncreature spell, torment each opponent. (They lose 3 life unless they discard a card or sacrifice a nonland permanent.)
{3}{U/B}{U/B}: Draw a card for each opponent with ten or more cards in their graveyard. You lose that much life.

Flash
When Agent of Equilibrium enters, destroy target creature or planeswalker an opponent controls that was dealt damage this turn.

Put target spell or nonland permanent on top of its owner's library.

When Harbinger of Growth enters, create a 1/1 green Saproling creature token.
{1}{G}, Sacrifice Harbinger of Growth: Populate. (Create a token that's a copy of a creature token you control.)

Shikai Revenant enters tapped.
At the beginning of your end step, if an opponent lost life this turn, you may return Shikai Revenant from your graveyard to your hand.

Vigilance
Renown 2 (When this creature deals combat damage to a player, if it isn't renowned, put two +1/+1 counters on it and it becomes renowned.)
{T}: Prevent the next X damage that would be dealt to target creature this turn, where X is Steelclad Investigator's power.

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.

{1}{G}{G}, Discard a card: Destroy target artifact or enchantment.
At the beginning of your end step, if twelve or more cards are in your graveyard, create two 3/3 green Beast creature tokens.

Target permanent phases out. (Then exile this card. You may cast the artifact later from exile.)

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Pressure {U} (You may cast this spell for its pressure cost if there are seven or more cards in your graveyard.)

When Raikai Seafarer enters, you may search your library for up to three cards named Raikai Seafarer, reveal them, put them into your hand, then shuffle.

When Luna enters, you may put a +1/+1 counter or loyalty counter on target creature or planeswalker.
Whenever another creature or planeswalker enters, you may exile Luna. Return her to the battlefield at the beginning of the next end step.

Planeswalker spells you cast cost {1} less to cast for each storied permanent you control. (Enchantments and legendary permanents are storied.)

Enchant land
Enchanted land has “{W}, {T}: You gain 2 life.”

GenTech Labs enters tapped.
{T}: Add {G} or {U}.
{G}{U}, {T}: Create a Function token with “This spell costs {1} less to cast if its mana value is 5 or greater.” Activate only if you have four or more cards in hand. (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Enchant creature
When Crown of Spores enters, germinate. (Put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)
Enchanted creature gets +2/+2.

Vigilance, reach
When Treeline Archer enters, mill four cards.
{5}{G}: Transform Treeline Archer. Activate only if it's attacking.

Activated abilities of nonland permanents cost {2} more to activate.

({T}: Add {G}.)
Moon of the Promised Day enters tapped.
{1}{G}, {T}: Scry 1.