Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Leyline of the Void

If Leyline of the Void is in your opening hand, you may begin the game with it on the battlefield.
If a card would be put into an opponent's graveyard from anywhere, exile it instead.

Dark Suspicions

At the beginning of each opponent's upkeep, that player loses X life, where X is the number of cards in that player's hand minus the number of cards in your hand.

Gibbering Descent

At the beginning of each player's upkeep, that player loses 1 life and discards a card.
Hellbent — Skip your upkeep step if you have no cards in hand.
Madness {2}{B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Raiders' Wake

Whenever an opponent discards a card, that player loses 2 life.
Raid — At the beginning of your end step, if you attacked this turn, target opponent discards a card.

Liliana's Caress

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

Oblivion Crown

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature has "Discard a card: This creature gets +1/+1 until end of turn."

Demonic Embrace

Enchant creature
Enchanted creature gets +3/+1, has flying, and is a Demon in addition to its other types.
You may cast Demonic Embrace from your graveyard by paying 3 life and discarding a card in addition to paying its other costs.

Dying Wail

Enchant creature
When enchanted creature dies, target player discards two cards.

Shrieking Affliction

At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, they lose 3 life.

Court of Ambition

When Court of Ambition enters, you become the monarch.
At the beginning of your upkeep, each opponent loses 3 life unless they discard a card. If you're the monarch, instead each opponent loses 6 life unless they discard two cards.

Brink of Madness

At the beginning of your upkeep, if you have no cards in hand, sacrifice Brink of Madness and target opponent discards their hand.

Planar Void

Whenever another card is put into a graveyard from anywhere, exile that card.

Forsaken Wastes

Players can't gain life.
At the beginning of each player's upkeep, that player loses 1 life.
Whenever Forsaken Wastes becomes the target of a spell, that spell's controller loses 5 life.

Necrogen Mists

At the beginning of each player's upkeep, that player discards a card.

Megrim

Whenever an opponent discards a card, Megrim deals 2 damage to that player.

Ordeal of Erebos

Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice Ordeal of Erebos.
When you sacrifice Ordeal of Erebos, target player discards two cards.

Dying to Serve

Whenever you discard one or more cards, create a tapped 2/2 black Zombie creature token. This ability triggers only once each turn.

Neheb, the Worthy

First strike
Other Minotaurs you control have first strike.
As long as you have one or fewer cards in hand, Minotaurs you control get +2/+0.
Whenever Neheb, the Worthy deals combat damage to a player, each player discards a card.

Phyrexian Scriptures

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Put a +1/+1 counter on up to one target creature. That creature becomes an artifact in addition to its other types.
II — Destroy all nonartifact creatures.
III — Exile all opponents' graveyards.

Lethal Vapors

Whenever a creature enters, destroy it.
{0}: Destroy Lethal Vapors. You skip your next turn. Any player may activate this ability.

Quest for the Nihil Stone

Whenever an opponent discards a card, you may put a quest counter on Quest for the Nihil Stone.
At the beginning of each opponent's upkeep, if that player has no cards in hand and Quest for the Nihil Stone has two or more quest counters on it, you may have that player lose 5 life.

Larceny

Whenever a creature you control deals combat damage to a player, that player discards a card.

Call the Bloodline

{1}, Discard a card: Create a 1/1 black Vampire Knight creature token with lifelink. Activate only once each turn.

Elspeth's Nightmare

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy target creature an opponent controls with power 2 or less.
II — Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.
III — Exile target opponent's graveyard.

Bottomless Pit

At the beginning of each player's upkeep, that player discards a card at random.