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,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 you control enters, 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.

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

When Runebreaker Mage enters, 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, you may switch target creature's power and toughness until end of turn.

When Sift Through False Leads enters, 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.

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

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

When Exiled Necromancer enters, return target permanent card with mana value 1 or less from your graveyard to the battlefield.

Fleshcrawler gets +1/+0 for each player that has lost life this turn.

At the beginning of your upkeep, mill a card.
Whenever you cast a spell from your graveyard, create a 2/2 green Wolf creature token.

Enchant creature
When Grip of Paranoia enters, enchanted creature's controller loses 2 life.
Enchanted creature gets -3/-1 and can't block.

Guardian of Dusk gets +X/+X, where X is the amount of life you've lost this turn.
When Guardian of Dusk has power 13 or greater, sacrifice it. If you do, you gain life equal to its power.

If a player would gain life, that player adds that much {C} instead.

Target creature gets -3/-3 until end of turn.
Target creature gets -3/-3 until end of turn.