msem-instigator

Whenever you sacrifice a Clue, you lose life equal to the number of Clues you control, then investigate twice. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Vanishing 3 (This permanent enters 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.)
Whenever a time counter is removed from Thespian's Finale, create a token that's a copy of target creature. Sacrifice that token at the beginning of your next upkeep.

Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
Flashback—{B}, Pay 2 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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

Create a 3/3 red Giant creature token with haste.
Creatures you control gain double strike until end of turn.

When Thunderstep Ved enters, it deals 1 damage to any target.

{3}: Put a +1/+1 counter on Tinkerer's Assistant.

Prowess
Whenever you cast an instant or sorcery spell, Tirenan Pyromancer deals 1 damage to each opponent.

Exile up to two target artifacts, creatures, and/or enchantments you control. Return those cards to the battlefield under your control at the beginning of the next end step.

Target creature gets -1/-1 until end of turn.
Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Equipped creature gets +0/+2.
When equipped creature dies, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
Equip {1}

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Tracker of Wild Places envisions a creature card, you may untap a permanent you control.

Puzzlebox (Begin the game with this and another card you own from outside the game in the command zone, locked. That card is face down until you unlock this.)
{2}, Discard your hand: Unlock Traitor's Gambit. If the revealed card is red, put it into your hand. Otherwise, put it on top of your library.

Enchant creature
Enchanted creature gets +2/+2 and has vigilance.
{2}{W}: Return Tranquil Endeavors from your graveyard to your hand.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast your first instant or sorcery spell each turn, copy that spell. You may choose new targets for the copies.

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.

Whenever Trusted Comrade and at least one other creature attack, create a 1/1 white Soldier creature token that's tapped and attacking.

Target player loses 1 life. Scry 1.
Fabled {2}{B} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that player.)

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)

Create four 3/3 green Elemental creature tokens.
Flashback {7}{G}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

When Uncovered Mine enters and at the beginning of your upkeep, return a random card from your graveyard to your hand.

When Undead Archivist enters, return target instant or sorcery card from your graveyard to your hand.
Revive {5}{U} ({5}{U}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Enchant land you control
Whenever enchanted land is tapped for mana, it produces an additional mana of that type.
{1}{G}, Sacrifice Under Untamed Skies: Destroy target creature with flying.

Choose one —
• Creatures you control become colorless Forest lands until end of turn. (They have “{T}: Add {G}” and lose all other types and abilities.)
• Lands you control become 2/2 green creatures in addition to their other types and gain haste until end of turn.

When Unwavering Sentinel enters, for each creature you control, create a white Aura enchantment token named Shield with “Enchant creature” and “If enchanted creature would be destroyed, instead remove all damage from it and sacrifice this Aura” attached to that creature.