Black Lotus

{T}, Sacrifice Black Lotus: Add three mana of any one color.

Painful Quandary

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

Mox Jet

Vicious Rumors

Vicious Rumors deals 1 damage to each opponent. Each opponent discards a card, then mills a card. You gain 1 life.

Tinybones, Trinket Thief

At the beginning of each end step, if an opponent discarded a card this turn, you draw a card and you lose 1 life.
{4}{B}{B}: Each opponent with no cards in hand loses 10 life.

Dark Deal

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

Jet Medallion

Black spells you cast cost {1} less to cast.

Dark Ritual

Tinybones, the Pickpocket

Deathtouch
Whenever Tinybones, the Pickpocket deals combat damage to a player, you may cast target nonland permanent card from that player's graveyard, and mana of any type can be spent to cast that spell.

Xyru Specter

Flying
Whenever Xyru Specter deals damage to an opponent, that player discards a card unless they challenge you. If challenged, and you show them two black cards in your hand, they must discard two cards.

Mirrored Lotus

Reflect {0} (As this enters, each opponent may pay {0}. When they do, they create a token copy of this except it lacks this ability.)
{T}, Exile Mirrored Lotus: Add three mana of any one color.

Burglar Rat

When this creature enters, each opponent discards a card.

Virus Beetle

When Virus Beetle enters, each opponent discards a card.

Tinybones, Bauble Burglar

Whenever an opponent discards a card, exile it from their graveyard with a stash counter on it.
During your turn, you may play cards you don't own with stash counters on them from exile, and mana of any type can be spent to cast those spells.
{3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.