Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Sign in Blood

Target player draws two cards and loses 2 life.

Underworld Dreams

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

Village Rites

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Sol Ring

Well of Lost Dreams

Whenever you gain life, you may pay {X}, where X is less than or equal to the amount of life you gained. If you do, draw X cards.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Gurgling Anointer

Flying
Whenever you draw your second card each turn, put a +1/+1 counter on Gurgling Anointer.
When Gurgling Anointer dies, return another target creature card with mana value less than or equal to Gurgling Anointer's power from your graveyard to the battlefield.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Baleful Mastery

You may pay {1}{B} rather than pay this spell's mana cost.
If the {1}{B} cost was paid, an opponent draws a card.
Exile target creature or planeswalker.

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

Dark Ritual

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Master of the Feast

Flying
At the beginning of your upkeep, each opponent draws a card.

Damnable Pact

Target player draws X cards and loses X life.

Arcane Signet

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

Withering Boon

As an additional cost to cast this spell, pay 3 life.
Counter target creature spell.

Fate Unraveler

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

Night's Whisper

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Alhammarret's Archive

If you would gain life, you gain twice that much life instead.
If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Dark Deal

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

Succumb to Temptation

Howling Mine

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.

Do or Die

Separate all creatures target player controls into two piles. Destroy all creatures in the pile of that player's choice. They can't be regenerated.

Eldritch Pact

Target player draws X cards and loses X life, where X is the number of cards in their graveyard.

Blood Pact

Read the Bones

Scry 2, then draw two cards. You lose 2 life.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

Teferi's Puzzle Box

At the beginning of each player's draw step, that player puts the cards in their hand on the bottom of their library in any order, then draws that many cards.

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Evolved Sleeper

{B}: Evolved Sleeper becomes a Human Cleric with base power and toughness 2/2.
{1}{B}: If Evolved Sleeper is a Cleric, put a deathtouch counter on it and it becomes a Phyrexian Human Cleric with base power and toughness 3/3.
{1}{B}{B}: If Evolved Sleeper is a Phyrexian, put a +1/+1 counter on it, then you draw a card and you lose 1 life.