msem-instigator

Once each turn, when you search your library, you may add {B}{B}.

Whenever a creature dealt damage by Truth Extractor this turn dies, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Flash
Flying
When Turela, Defiant Angel enters, exile all other creatures you control. Return them to the battlefield under their owner's control at the beginning of the next end step.

Flying, lifelink
Sacrifice a creature: Until end of turn, Turned Watcher gets +1/+0 and gains “Whenever Turned Watcher deals combat damage to a player, draw a card.”

This spell costs {X} less to cast, where X is the power of the creature it targets.
Tyrant's Reckoning deals 4 damage to target creature.

Cast this spell only if you control a creature.
Exile all creatures.

Whenever a Wizard you control deals damage to a player, draw a card.

When Uncovered Idol enters, scry 1.
{1}, Sacrifice Uncovered Idol: Put a +1/+1 counter on target creature. Activate only as a sorcery.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Undercity Diplomat can't be blocked by marked creatures.

{T}, Sacrifice a permanent: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

At the beginning of your upkeep, reveal the top card of your library. If it has the same name as a card in your graveyard, put the revealed card into your hand. Otherwise, put it into your graveyard.

{6}{W}: Tap all creatures target player controls.

Choose one, then choose another for each card named Unraveling in your graveyard.
• Counter up to one target spell.
• Scry 2, then draw a card.
• Up to three target lands your opponents control don't untap during their controller's next untap step.
• Creatures your opponents control get -4/-0 until end of turn.

Gain control of target creature until end of turn. Untap that creature. It gains haste and is marked until end of turn.

All creatures have “When this creature enters, destroy target creature with a lesser mana value.”

{4}{B}{B}: Return Urchin Defector from your graveyard to the battlefield transformed.

Menace

Target creature gets +2/+2 and gains indestructible until end of turn.

Hexproof
As long as an opponent controls a permanent you own, Vault Sentinel gets +4/+4.

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

Whenever you cast a spell during an opponent's turn, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
Whenever a creature you control enters, each opponent loses 1 life.
I, II — Create a 1/1 black Actor creature token with lifelink.
III — Each opponent loses life equal to the number of tokens you control. You gain life equal to the life lost this way.

Whenever you sacrifice a Clue, Vivian's Vanguard gets +2/+0 and gains flying until end of turn.

[+1]: Exile up to one other target permanent until the beginning of its owner's next end step.
[–1]: Return another target planeswalker to its owner's hand.
[–6]: You get an emblem with “Whenever a permanent leaves the battlefield, each opponent discards a card.”

Target creature gets +X/+X and gains vigilance until your next turn, where X is the number of creatures you control.