msem-instigator

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

When Sights Beyond enters the battlefield, scry 3.
Concord — At the beginning of your upkeep, if there are four or more card types among permanents you control, draw a card.

Flash
Flying
When Spectrum Archmage enters the battlefield, return target spell to its owner's hand, then abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)

Counter target noncreature spell unless its controller pays {2}.

Flying
{X}{U}: Gain control of target nonland permanent with mana value X until Sphinx of Supremacy leaves the battlefield. Activate only as a sorcery.

Counter target noncreature spell. Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

If a creature entering the battlefield under your control causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
{1}{U}, {T}: Exile another target creature. Return it to the battlefield under its owner's control at the beginning of the next end step.

Flying
When Syrina, the Dragon Queen enters the battlefield, gain control of target nonland permanent for as long as you control Syrina, the Dragon Queen.
{2}{U}: Exile Syrina, the Dragon Queen. Return her to the battlefield at the beginning of the next end step.

Enchant nonland permanent
Vanishing 3 (This permanent enters the battlefield with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
You control enchanted permanent.

When Terraformer's Globe enters the battlefield, draw a card.
{T}: Target land you control becomes the basic land type of your choice until end of turn.

Instant and sorcery spells you control have leitmotif. (Exile that spell as it resolves if you cast it from your hand. When you next cast a spell that shares a color with that card, you may cast it from exile without paying its mana cost.)

Whenever you cast a noncreature spell, create a 1/1 colorless Construct artifact creature token.

Flash
When Veilborn Meddler enters the battlefield, counter target spell if its mana value is less than or equal to Veilborn Meddler's power.
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on Veilborn Meddler.

Flash
Flying
Sacrifice Vengeful Messenger: Counter target noncreature spell unless its controller pays {2}.

Eureka! (At the beginning of each end step, you get a research counter if you cast a spell this turn. Then if you have eight or more research counters, remove them and create a Masterpiece token of your choice.)
[+1]: Untap up to one target artifact you control.
[–2]: Draw three cards. Then discard two cards unless you discard an artifact card.

Whenever Wakeborne Kraken or another Kraken, Leviathan, Octopus, or Serpent enters the battlefield under your control, you may return target creature an opponent controls to its owner's hand.
Whenever a creature an opponent controls leaves the battlefield, if it didn't die, draw a card.

Draw two cards, then discard two cards. Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Exile the top five cards of your library. An opponent separates them into two piles. You may put one pile into your hand or draw two cards. Then put the rest of the piles into your graveyard.

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
You may have Witch of Shifting Waters enter the battlefield as a copy of any creature on the battlefield, except it's an enchantment in addition to its other types.

Flash
When Witch's Invocation enters the battlefield, draw a card.
You may cast spells as though they had flash.

Wanderlust — This spell has flash as long as you control four or more differently named lands.
Draw four cards.

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

At the beginning of your upkeep, if you control four or more Swamps, you may exile target creature card from your graveyard. If you do, create a tapped token that's a copy of it except it's a black Mummy.

Reconstruct {4}{B}{B}{B} (You may cast this from your graveyard for its reconstruct cost reduced by the mana value of a permanent you sacrifice as you cast it this way. Then exile this.)
Destroy all creatures. If The Afterlife Takes Its Due was reconstructed, create an X/X black Zombie Horror creature token, where X is the number of creature cards that have been put into graveyards this turn.

Deception {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
When Aguri, Shadow of Doubt enters the battlefield, target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.