Tethaleeg, the Opulent can't be blocked.
Whenever a player casts a noncreature spell, draw a card.
You may cast Tethaleeg, the Opulent from your graveyard by discarding two cards in addition to paying its other costs.

Choose one —
• Change the target of target spell with a single target.
• Any number of target players shuffle their graveyards into their libraries.

You may have Uncanny Duplicant enter as a copy of any creature on the battlefield.
Undercover

Enchant creature
Enchanted creature gets +1/+0, can't be blocked, is colorless, and has no name.

When Woman with a Story enters, you may return target creature to its owner's hand.

All creatures get -1/-1 until end of turn.
Undercover

{3}{B}: Alley Shade gets +2/+2 and gains lifelink until end of turn.

Target creature gets -2/-2 until end of turn. That creature's controller loses 2 life.

{X}, Discard a card with mana value X: Exile target creature with mana value X. Put a hit counter on that card. Then if there are six or more cards in exile with hit counters on them, you win the game.

Destroy target creature. Scry 1.

Destroy target creature. That creature's controller investigates.

At the beginning of each end step, if you've disturbed the peace this turn, each opponent loses 1 life and you gain 1 life.

Each player discards three cards. When one or more players discards one or more cards this way, choose one —
• You draw three cards and you lose 3 life.
• Exile two cards from an opponent's graveyard. You may cast those cards for as long as they remains exiled, and mana of any type can be spent to cast those spells.

When Dame on the Run dies, investigate.

Search your library for a card, put that card into your hand, then shuffle.
Investigate.

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Each opponent loses X life. You gain life equal to the life lost this way.

Enchant creature
Whenever enchanted creature becomes tapped, destroy it.

Return target creature card from your graveyard to your hand.
Undercover

Destroy target creature or planeswalker. If you cast Framed Murder from exile, you gain 2 life.
Undercover

Menace
{T}, Sacrifice Hound of Rounded Corners: Each opponent discards a card. Activate only as a sorcery.

[+1]: Create a 1/1 black Zombie Cat creature token with “When this creature dies, target opponent discards a card.”
[–2]: Sacrifice a creature. If you do, return target creature card from your graveyard to the battlefield.
[–9]: Target opponent gets an emblem with “At the beginning of your upkeep, if you have one or fewer cards in hand, you lose the game.”

Liliana's Goon can't block.
At the beginning of each end step, if you've disturbed the peace this turn, you may return Liliana's Goon from your graveyard to your hand.

Whenever an opponent discards one or more cards, that player loses 2 life.
At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, they lose 2 life.

When Lorre Blackmailer enters, target opponent discards a card.