Braids's Frightful Return

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — You may sacrifice a creature. If you do, each opponent discards a card.
II — Return target creature card from your graveyard to your hand.
III — Target opponent may sacrifice a nonland, nontoken permanent of their choice. If they don't, they lose 2 life and you draw a card.

Erebos's Emissary

Bestow {5}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Discard a creature card: This creature gets +2/+2 until end of turn. If this permanent is an Aura, enchanted creature gets +2/+2 until end of turn instead.
Enchanted creature gets +3/+3.

Whip of Erebos

Creatures you control have lifelink.
{2}{B}{B}, {T}: Return target creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step. If it would leave the battlefield, exile it instead of putting it anywhere else. Activate only as a sorcery.

Empty the Pits

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Create X tapped 2/2 black Zombie creature tokens.

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Gravedigger

When this creature enters, you may return target creature card from your graveyard to your hand.

Bladebrand

Target creature gains deathtouch until end of turn.
Draw a card.

Agent of the Fates

Deathtouch
Heroic — Whenever you cast a spell that targets this creature, each opponent sacrifices a creature of their choice.

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

Reign of the Pit

Each player sacrifices a creature of their choice. Create an X/X black Demon creature token with flying, where X is the total power of the creatures sacrificed this way.

Murder

Duty-Bound Dead

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{3}{B}: Regenerate this creature. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Transmogrant Altar

{B}, {T}, Sacrifice a creature: Add {C}{C}{C}.
{2}, {T}, Sacrifice a creature: Create a 3/3 colorless Zombie artifact creature token. Activate only as a sorcery.

Leaden Myr

Skullport Merchant

When this creature enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
{1}{B}, Sacrifice another creature or a Treasure: Draw a card.

Blood Bairn

Sacrifice another creature: This creature gets +2/+2 until end of turn.

Annihilating Glare

As an additional cost to cast this spell, pay {4} or sacrifice an artifact or creature.
Destroy target creature or planeswalker.

Slum Reaper

When this creature enters, each player sacrifices a creature of their choice.

Barter in Blood

Each player sacrifices two creatures of their choice.

Dokuchi Shadow-Walker

Ninjutsu {3}{B} ({3}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Extinguish the Light

Destroy target creature or planeswalker. If its mana value was 3 or less, you gain 3 life.

Murderous Cut

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Destroy target creature.

Undercity Necrolisk

{1}, Sacrifice another creature: Put a +1/+1 counter on this creature. It gains menace until end of turn. Activate only as a sorcery. (It can't be blocked except by two or more creatures.)

Abhorrent Overlord

Flying
When this creature enters, create a number of 1/1 black Harpy creature tokens with flying equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
At the beginning of your upkeep, sacrifice a creature.

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Phage the Untouchable

When Phage enters, if you didn't cast it from your hand, you lose the game.
Whenever Phage deals combat damage to a creature, destroy that creature. It can't be regenerated.
Whenever Phage deals combat damage to a player, that player loses the game.

Sanitarium Skeleton

{2}{B}: Return this card from your graveyard to your hand.

Fractured Powerstone

{T}: Add {C}.
{T}: Roll the planar die. Activate only as a sorcery.

Crypt Ghast

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever you tap a Swamp for mana, add an additional {B}.

Undercity Scrounger

{T}: Create a Treasure token. Activate only if a creature died this turn. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Swamp

Charcoal Diamond

This artifact enters tapped.
{T}: Add {B}.

Dokuchi Silencer

Ninjutsu {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, you may discard a creature card. When you do, destroy target creature or planeswalker that player controls.

Altar's Reap

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

Painful Lesson

Target player draws two cards and loses 2 life.

Beacon of Unrest

Put target artifact or creature card from a graveyard onto the battlefield under your control. Shuffle Beacon of Unrest into its owner's library.

Rise from the Grave

Put target creature card from a graveyard onto the battlefield under your control. That creature is a black Zombie in addition to its other colors and types.

Cast Down

Toshiro Umezawa

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)
Whenever a creature an opponent controls dies, you may cast target instant card from your graveyard. If that spell would be put into a graveyard, exile it instead.

Falkenrath Torturer

Sacrifice a creature: This creature gains flying until end of turn. If the sacrificed creature was a Human, put a +1/+1 counter on this creature.

Corrupted Grafstone

This artifact enters tapped.
{T}: Choose a color of a card in your graveyard. Add one mana of that color.

Phyrexian Rager

When this creature enters, you draw a card and you lose 1 life.

Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Chainflail Centipede

Whenever this creature or equipped creature attacks, it gets +2/+0 until end of turn.
Reconfigure {2} ({2}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Bloodthrone Vampire

Sacrifice a creature: This creature gets +2/+2 until end of turn.

Leech Gauntlet

Lifelink
Equipped creature has lifelink.
Reconfigure {4} ({4}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Blood Scrivener

If you would draw a card while you have no cards in hand, instead you draw two cards and you lose 1 life.

Launch Party

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature. Its controller loses 2 life.

Devour Flesh

Target player sacrifices a creature of their choice, then gains life equal to that creature's toughness.

Echo of Death's Wail

Flying, haste
When this creature enters, gain control of all Rat tokens.
Whenever this creature attacks, you may sacrifice another creature. If you do, draw a card.

Tribute to Horobi

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Each opponent creates a 1/1 black Rat Rogue creature token.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Tribute to Horobi // Echo of Death's Wail

Ogre Slumlord

Whenever another nontoken creature dies, you may create a 1/1 black Rat creature token.
Rats you control have deathtouch.

Tyrannical Pitlord

Flying, trample
As this creature enters, choose another creature you control.
The chosen creature gets +3/+3 and has flying.
When this creature leaves the battlefield, sacrifice the chosen creature.

Ravenous Chupacabra

When this creature enters, destroy target creature an opponent controls.

Filigree Familiar

When this creature enters, you gain 2 life.
When this creature dies, draw a card.

Oathkeeper, Takeno's Daisho

Equipped creature gets +3/+1.
Whenever equipped creature dies, return that card to the battlefield under your control if it's a Samurai card.
When Oathkeeper is put into a graveyard from the battlefield, exile equipped creature.
Equip {2}

Carrier Thrall

When this creature dies, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this token: Add {C}."

Doom Blade

Endless Obedience

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Put target creature card from a graveyard onto the battlefield under your control.

Death Wind

Target creature gets -X/-X until end of turn.

Windgrace Acolyte

Flying
When this creature enters, mill three cards and you gain 3 life.

Eerie Soultender

When this creature enters, mill three cards. (Put the top three cards of your library into your graveyard.)
{4}{B}, Exile this card from your graveyard: Return another target creature card from your graveyard to your hand.

Grisly Spectacle

Destroy target nonartifact creature. Its controller mills cards equal to that creature's power.