Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Moltensteel Dragon

({R/P} can be paid with either {R} or 2 life.)
Flying
{R/P}: Moltensteel Dragon gets +1/+0 until end of turn.

Reliquary Tower

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

Arcane Signet

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

Wall of Blood

Defender (This creature can't attack.)
Pay 1 life: Wall of Blood gets +1/+1 until end of turn.

Stargaze

Look at twice X cards from the top of your library. Put X cards from among them into your hand and the rest into your graveyard. You lose X life.

Festival of Embers

During your turn, you may cast instant and sorcery spells from your graveyard by paying 1 life in addition to their other costs.
If a card or token would be put into your graveyard from anywhere, exile it instead.
{1}{R}: Sacrifice Festival of Embers.

Orcus, Prince of Undeath

Flying, trample
When Orcus, Prince of Undeath enters, choose one —
• Each other creature gets -X/-X until end of turn. You lose X life.
• Return up to X target creature cards with total mana value X or less from your graveyard to the battlefield. They gain haste until end of turn.

Night's Whisper

Crackle with Power

Crackle with Power deals five times X damage to each of up to X targets.

Ribbons

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Each opponent loses X life.

Cut // Ribbons

Sol Ring

Judith, Carnage Connoisseur

Whenever you cast an instant or sorcery spell, choose one —
• That spell gains deathtouch and lifelink.
• Create a 2/2 red Imp creature token with "When this creature dies, it deals 2 damage to each opponent."

Command Tower

Blood Celebrant

{B}, Pay 1 life: Add one mana of any color.

Erebos's Intervention

Choose one —
• Target creature gets -X/-X until end of turn. You gain X life.
• Exile up to twice X target cards from graveyards.

Tavern Swindler

{T}, Pay 3 life: Flip a coin. If you win the flip, you gain 6 life.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Rakdos Signet

Stormfist Crusader

Menace
At the beginning of your upkeep, each player draws a card and loses 1 life.

K'rrik, Son of Yawgmoth

({B/P} can be paid with either {B} or 2 life.)
Lifelink
For each {B} in a cost, you may pay 2 life rather than pay that mana.
Whenever you cast a black spell, put a +1/+1 counter on K'rrik, Son of Yawgmoth.

Rowan, Scion of War

Menace
{T}: Spells you cast this turn that are black and/or red cost {X} less to cast, where X is the amount of life you lost this turn. Activate only as a sorcery.

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.)

Lightning Greaves

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

Jaya's Immolating Inferno

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Jaya's Immolating Inferno deals X damage to each of up to three targets.