Tergrid's Lantern

{T}: Target player loses 3 life unless they sacrifice a nonland permanent of their choice or discard a card.
{3}{B}: Untap Tergrid's Lantern.

Tergrid, God of Fright

Menace
Whenever an opponent sacrifices a nontoken permanent or discards a permanent card, you may put that card from a graveyard onto the battlefield under your control.

Tergrid, God of Fright // Tergrid's Lantern

Megrim

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

Dragonskull Summit

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Swamp

Underworld Dreams

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

Rakdos Signet

Wheel of Fate

Suspend 4—{1}{R} (Rather than cast this card from your hand, pay {1}{R} and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Each player discards their hand, then draws seven cards.

Liliana's Caress

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

Dark Deal

Each player discards all the cards in their hand, then draws that many cards minus one.

Barbed Shocker

Trample, haste
Whenever Barbed Shocker deals damage to a player, that player discards all the cards in their hand, then draws that many cards.

Mountain

Tourach, Dread Cantor

Kicker {B}{B} (You may pay an additional {B}{B} as you cast this spell.)
Protection from white
Whenever an opponent discards a card, put a +1/+1 counter on Tourach, Dread Cantor.
When Tourach enters, if it was kicked, target opponent discards two cards at random.

Sorcerer's Wand

Equipped creature has "{T}: This creature deals 1 damage to target player or planeswalker. If this creature is a Wizard, it deals 2 damage instead."
Equip {3}

Raise Dead

Return target creature card from your graveyard to your hand.

Kederekt Parasite

Whenever an opponent draws a card, if you control a red permanent, you may have Kederekt Parasite deal 1 damage to that player.

Chandra's Defeat

Chandra's Defeat deals 5 damage to target red creature or red planeswalker. If that permanent is a Chandra planeswalker, you may discard a card. If you do, draw a card.

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.

Rakdos Carnarium

Rakdos Carnarium enters tapped.
When Rakdos Carnarium enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.