Confounding Riddle

Choose one —
• Look at the top four cards of your library. Put one of them into your hand and the rest into your graveyard.
• Counter target spell unless its controller pays {4}.

Uchbenbak, the Great Mistake

Vigilance, menace
Descend 8 — {4}{U}{B}: Return this card from your graveyard to the battlefield with a finality counter on it. Activate only if there are eight or more permanent cards in your graveyard and only as a sorcery. (If a creature with a finality counter on it would die, exile it instead.)

Powerstone Fracture

As an additional cost to cast this spell, sacrifice an artifact or creature.
Destroy target creature or planeswalker.

Bitter Triumph

As an additional cost to cast this spell, discard a card or pay 3 life.
Destroy target creature or planeswalker.

Swamp

Lazotep Convert

You may have Lazotep Convert enter as a copy of any creature card in a graveyard, except it's a 4/4 black Zombie in addition to its other colors and types.

Invasion of Amonkhet

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Amonkhet enters, each player mills three cards, then each opponent discards a card and you draw a card. (To mill three cards, a player puts the top three cards of their library into their graveyard.)

Invasion of Amonkhet // Lazotep Convert

Duress

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

Ravenous Gigamole

When this creature enters, mill three cards. You may put a creature card from among the cards milled this way into your hand. If you don't, put a +1/+1 counter on this creature. (To mill a card, put the top card of your library into your graveyard.)

Echo of Dusk

Descend 4 — As long as there are four or more permanent cards in your graveyard, this creature gets +1/+1 and has lifelink.

Cold Case Cracker

Flying
When this creature dies, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Conduit Pylons

When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Island

Screaming Phantom

Flying
Whenever this creature attacks, mill a card. (Put the top card of your library into your graveyard.)

Hollow Marauder

This spell costs {1} less to cast for each creature card in your graveyard.
Flying
When this creature enters, any number of target opponents each discard a card. For each of those opponents who didn't discard a card with mana value 4 or greater, draw a card.

Soulcoil Viper

{B}, {T}, Sacrifice this creature: Return target creature card from your graveyard to the battlefield with a finality counter on it. Activate only as a sorcery. (If a creature with a finality counter on it would die, exile it instead.)

Diresight

Surveil 2, then draw two cards. You lose 2 life. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Nightwhorl Hermit

Vigilance
Threshold — As long as seven or more cards are in your graveyard, this creature gets +1/+0 and can't be blocked.

Bonebind Orator

{3}{B}, Exile this card from your graveyard: Return another target creature card from your graveyard to your hand.

Captivating Cave

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{4}, {T}, Sacrifice this land: Put two +1/+1 counters on target creature. Activate only as a sorcery.

Murder

Hidden Cataract

This land enters tapped.
{T}: Add {U}.
{4}{U}, {T}, Sacrifice this land: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Fanatical Offering

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Map token. (It's an artifact with "{1}, {T}, Sacrifice this token: Target creature you control explores. Activate only as a sorcery.")

Deathcap Marionette

Deathtouch
When this creature enters, you may mill two cards. (You may put the top two cards of your library into your graveyard.)

Another Chance

You may mill two cards. Then return up to two creature cards from your graveyard to your hand. (To mill two cards, put the top two cards of your library into your graveyard.)

Undercity Eliminator

When this creature enters, you may sacrifice an artifact or creature. When you do, exile target creature an opponent controls.

Moment of Truth

Look at the top three cards of your library. Put one of those cards into your hand, one into your graveyard, and one on the bottom of your library.