Consuming Aberration

Consuming Aberration's power and toughness are each equal to the number of cards in your opponents' graveyards.
Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Lotus Vale

If Lotus Vale would enter, sacrifice two untapped lands instead. If you do, put Lotus Vale onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add three mana of any one color.

The Royal Scions

+1: Draw a card, then discard a card.
+1: Target creature gets +2/+0 and gains first strike and trample until end of turn.
−8: Draw four cards. When you do, The Royal Scions deals damage to any target equal to the number of cards in your hand.

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Blood Tribute

Kicker—Tap an untapped Vampire you control. (You may tap a Vampire you control in addition to any other costs as you cast this spell.)
Target opponent loses half their life, rounded up. If this spell was kicked, you gain life equal to the life lost this way.

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on Bloodchief Ascension. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if Bloodchief Ascension has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Liliana's Caress

Whenever an opponent discards a card, that player loses 2 life.

Snow-Covered Island

Snow-Covered Mountain

Head Games

Target opponent puts the cards from their hand on top of their library. Search that player's library for that many cards. The player puts those cards into their hand, then shuffles.

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Enter the Infinite

Draw cards equal to the number of cards in your library, then put a card from your hand on top of your library. You have no maximum hand size until your next turn.

Izzet Signet

Underworld Dreams

Whenever an opponent draws a card, Underworld Dreams deals 1 damage to that player.

The Haunt of Hightower

Flying, lifelink
Whenever The Haunt of Hightower attacks, defending player discards a card.
Whenever a card is put into an opponent's graveyard from anywhere, put a +1/+1 counter on The Haunt of Hightower.

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Traumatize

Target player mills half their library, rounded down.

Nekusar, the Mindrazer

At the beginning of each player's draw step, that player draws an additional card.
Whenever an opponent draws a card, Nekusar, the Mindrazer deals 1 damage to that player.

Fate Unraveler

Whenever an opponent draws a card, Fate Unraveler deals 1 damage to that player.

Temporal Extortion

When you cast this spell, any player may pay half their life, rounded up. If a player does, counter Temporal Extortion.
Take an extra turn after this one.

Snow-Covered Swamp

Havoc Festival

Players can't gain life.
At the beginning of each player's upkeep, that player loses half their life, rounded up.

Fraying Omnipotence

Each player loses half their life, then discards half the cards in their hand, then sacrifices half the creatures they control. Round up each time.