Disdainful Stroke

Counter target spell with mana value 4 or greater.

Aven Heartstabber

Flying
As long as there are five or more mana values among cards in your graveyard, Aven Heartstabber gets +2/+2 and has deathtouch.
When Aven Heartstabber dies, mill two cards, then draw a card.

Revel Ruiner

Menace (This creature can't be blocked except by two or more creatures.)
When Revel Ruiner enters, it connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Snooping Newsie

When Snooping Newsie enters, mill two cards. (Put the top two cards of your library into your graveyard.)
As long as there are five or more mana values among cards in your graveyard, Snooping Newsie gets +1/+1 and has lifelink.

Illicit Shipment

Casualty 3 (As you cast this spell, you may sacrifice a creature with power 3 or greater. When you do, copy this spell.)
Search your library for a card, put it into your hand, then shuffle.

Incriminate

Choose two target creatures controlled by the same player. That player sacrifices one of them.

Psionic Snoop

Flash
When Psionic Snoop enters, it connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Dusk Mangler

As an additional cost to cast this spell, sacrifice a creature, discard a card, or pay 4 life.
When Dusk Mangler enters, each opponent sacrifices a creature, discards a card, and loses 4 life.

Extract the Truth

Choose one —
• Target opponent reveals their hand. You may choose a creature, enchantment, or planeswalker card from it. That player discards that card.
• Target opponent sacrifices an enchantment.

Dig Up the Body

Casualty 1 (As you cast this spell, you may sacrifice a creature with power 1 or greater. When you do, copy this spell.)
Mill two cards, then you may return a creature card from your graveyard to your hand. (To mill a card, put the top card of your library into your graveyard.)

Demon's Due

Scry 2, then draw two cards. You lose 2 life.

Ominous Parcel

{2}, {T}, Sacrifice Ominous Parcel: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{5}, {T}, Sacrifice Ominous Parcel: It deals 4 damage to target creature.

Security Bypass

Enchant creature
As long as enchanted creature is attacking alone, it can't be blocked.
Enchanted creature has "Whenever this creature deals combat damage to a player, it connives." (Its controller draws a card, then discards a card. If they discarded a nonland card, they put a +1/+1 counter on this creature.)

Fake Your Own Death

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control and you create a Treasure token." (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Make Disappear

Casualty 1 (As you cast this spell, you may sacrifice a creature with power 1 or greater. When you do, copy this spell and you may choose a new target for the copy.)
Counter target spell unless its controller pays {2}.

Sewer Crocodile

{3}{U}: Sewer Crocodile can't be blocked this turn. This ability costs {3} less to activate if there are five or more mana values among cards in your graveyard.

Join the Maestros

Casualty 2 (As you cast this spell, you may sacrifice a creature with power 2 or greater. When you do, copy this spell.)
Create a 4/3 black Ogre Warrior creature token.

Raffine's Silencer

When Raffine's Silencer enters, it connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)
When Raffine's Silencer dies, target creature an opponent controls gets -X/-X until end of turn, where X is Raffine's Silencer's power.

Deal Gone Bad

Target creature gets -3/-3 until end of turn. Target player mills three cards. (They put the top three cards of their library into their graveyard.)