Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Raucous Theater

({T}: Add {B} or {R}.)
Raucous Theater enters tapped.
When Raucous Theater enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Pain Magnification

Whenever an opponent is dealt 3 or more damage by a single source, that player discards a card.

Zoyowa Lava-Tongue

Deathtouch
At the beginning of your end step, if you descended this turn, each opponent may discard a card or sacrifice a permanent. Zoyowa Lava-Tongue deals 3 damage to each opponent who didn't. (You descended if a permanent card was put into your graveyard from anywhere.)

Waste Not

Whenever an opponent discards a creature card, create a 2/2 black Zombie creature token.
Whenever an opponent discards a land card, add {B}{B}.
Whenever an opponent discards a noncreature, nonland card, draw a card.

Sol Ring

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Geth's Grimoire

Whenever an opponent discards a card, you may draw a card.

Rix Maadi, Dungeon Palace

{T}: Add {C}.
{1}{B}{R}, {T}: Each player discards a card. Activate only as a sorcery.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Kroxa, Titan of Death's Hunger

When Kroxa enters, sacrifice it unless it escaped.
Whenever Kroxa enters or attacks, each opponent discards a card, then each opponent who didn't discard a nonland card this way loses 3 life.
Escape—{B}{B}{R}{R}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Liliana's Caress

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

Not Dead After All

Until end of turn, target creature you control gains "When this creature dies, return it to the battlefield tapped under its owner's control, then create a Wicked Role token attached to it." (Enchanted creature gets +1/+1. When this Aura is put into a graveyard, each opponent loses 1 life.)