msem-instigator

Put target creature with power X or less on top of its owner's library.
Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

{T}: Scry 1.
{1}{U}, {T}: Reveal the bottom card of your library. If it's an artifact or enchantment card, put it into your hand.

Target creature gets -4/-0 until end of turn.
Flashback {U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Flash
Flying
When Mischievous Sprite enters the battlefield,you may tap or untap target permanent.

Search your library for up to six cards and exile them face down. Shuffle, then draw a card.

At the beginning of your upkeep, look at the top card of your library. If it's an artifact or enchantment card, you may reveal it and put it into your hand. Otherwise, you may put it on the bottom of your library.
If you would begin a combat phase, you may skip that phase and begin an additional upkeep step instead.

Whenever an artifact or enchantment enters the battlefield under your control, target player mills two cards.

Whenever you cast an instant spell during your main phase, copy that spell. You may choose new targets for the copies.

Return Portal to the Unknown to its owner's hand: Add {U}{U}{U}. The next card you cast this turn can be cast as though it had flash.

Draw two cards, then discard two cards. Then if you cast Price of Wisdom from your graveyard, create a 3/3 blue Sphinx creature token with flying.
Flashback {4}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

When Relearn History enters the battlefield, draw two cards.
You have no maximum hand size.

When Rune-Scribe's Apprentice enters the battlefield, target player mills four cards.

When Runebreaker Mage enters the battlefield, return another target nonland permanent you control and target nonland permanent you don't control to their owner's hands.

Flash
When Scholar of Reflections enters the battlefield, you may switch target creature's power and toughness until end of turn.

When Serafina's Gift enters the battlefield, if you cast it, target opponent gains control of it.
At the beginning of your upkeep, draw three cards, then discard two cards.

When Sift Through False Leads enters the battlefield, exile the top five cards of your library, then investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
{2}, Sacrifice a Clue: Put a card exiled with Sift Through False Leads into your hand.

Flash
Flying
Whenever you cast a spell during an opponent's turn, target permanent doesn't untap during its controller's next untap step.

Flying
When Sphinx of Ill Omens enters the battlefield, return target permanent to its owner's hand.
Discard a card: Target creature or player gains hexproof until end of turn.

When Titan of Lake Vasil enters the battlefield, untap up to four target permanents.
{3}{U}: Draw a card.

Whenever you cast a spell from your graveyard, you may return target nonland permanent to its owner's hand.
Sacrifice a Clue: Return Trespasser of the Gallows from your graveyard to your hand.

When Warden of the Archives enters the battlefield, if you cast it, tap up to four target permanents.

Enchant creature you control
Enchanted creature gets +1/+1 and has hexproof and “{T}: Target player mills two cards.”
Whenever you play a land, untap enchanted creature.

When Archivist Heretic enters the battlefield, you lose 1 life, then investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Create a 5/3 black Horror creature token.
Flashback {1}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Whenever a token creature you control dies, each opponent loses 2 life.