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.

Phyrexian Vivisector

Whenever a creature you control dies, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Decanter of Endless Water

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

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Shambling Ghast

When Shambling Ghast dies, choose one —
• Target creature an opponent controls gets -1/-1 until end of turn.
• Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Sivriss, Nightmare Speaker

{T}, Sacrifice another creature or an artifact: For each opponent, you mill a card, then return that card from your graveyard to your hand unless that player pays 3 life. (To mill a card, put the top card of your library into your graveyard.)
Choose a Background (You can have a Background as a second commander.)

Demon's Disciple

When Demon's Disciple enters, each player sacrifices a creature or planeswalker of their choice.

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Ghost Quarter

{T}: Add {C}.
{T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Elvish Doomsayer

When Elvish Doomsayer dies, each opponent discards a card.

The Eldest Reborn

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Each opponent sacrifices a creature or planeswalker of their choice.
II — Each opponent discards a card.
III — Put target creature or planeswalker card from a graveyard onto the battlefield under your control.

Unearth

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Omen of the Dead

Flash
When Omen of the Dead enters, return target creature card from your graveyard to your hand.
{2}{B}, Sacrifice Omen of the Dead: Scry 2.

Warlock Class

(Gain the next level as a sorcery to add its ability.)
At the beginning of your end step, if a creature died this turn, each opponent loses 1 life.
{1}{B}: Level 2
When this Class becomes level 2, look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
{6}{B}: Level 3
At the beginning of your end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Persistent Specimen

{2}{B}: Return Persistent Specimen from your graveyard to the battlefield tapped.

Dark Ritual

Leaden Myr

Vindictive Vampire

Whenever another creature you control dies, Vindictive Vampire deals 1 damage to each opponent and you gain 1 life.

Morbid Opportunist

Whenever one or more other creatures die, draw a card. This ability triggers only once each turn.

Gods' Eye, Gate to the Reikai

{T}: Add {C}.
When Gods' Eye, Gate to the Reikai is put into a graveyard from the battlefield, create a 1/1 colorless Spirit creature token.

Feign Death

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Elspeth's Nightmare

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy target creature an opponent controls with power 2 or less.
II — Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.
III — Exile target opponent's graveyard.

Undying Malice

Darksteel Ingot

Indestructible (Effects that say "destroy" don't destroy this artifact.)
{T}: Add one mana of any color.

Virus Beetle

When Virus Beetle enters, each opponent discards a card.

Agent of the Iron Throne

Commander creatures you own have "Whenever an artifact or creature you control is put into a graveyard from the battlefield, each opponent loses 1 life."

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Despondency

Enchant creature
Enchanted creature gets -2/-0.
When Despondency is put into a graveyard from the battlefield, return Despondency to its owner's hand.

Swamp

Fleshbag Marauder

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

Ghoulish Procession

Whenever one or more nontoken creatures die, create a 2/2 black Zombie creature token with decayed. This ability triggers only once each turn. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)

Blood Fountain

When Blood Fountain enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")
{3}{B}, {T}, Sacrifice Blood Fountain: Return up to two target creature cards from your graveyard to your hand.

Dockside Chef

{1}{B}, Sacrifice an artifact or creature: Draw a card.

Supernatural Stamina

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Fallen Ideal

Enchant creature
Enchanted creature has flying and "Sacrifice a creature: This creature gets +2/+1 until end of turn."
When Fallen Ideal is put into a graveyard from the battlefield, return Fallen Ideal to its owner's hand.

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Smallpox

Each player loses 1 life, discards a card, sacrifices a creature of their choice, then sacrifices a land of their choice.

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Gravelighter

Flying
When Gravelighter enters, draw a card if a creature died this turn. Otherwise, each player sacrifices a creature of their choice.

Doom Blade

Falkenrath Noble

Flying
Whenever Falkenrath Noble or another creature dies, target player loses 1 life and you gain 1 life.

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Drag to the Underworld

This spell costs {X} less to cast, where X is your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
Destroy target creature.

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Commander's Sphere

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

Forever Young

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.

Dunes of the Dead

{T}: Add {C}.
When Dunes of the Dead is put into a graveyard from the battlefield, create a 2/2 black Zombie creature token.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Eaten Alive

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Exile target creature or planeswalker.

Chime of Night

Enchant creature
When Chime of Night is put into a graveyard from the battlefield, destroy target nonblack creature.

Clattering Augur

Clattering Augur can't block.
When Clattering Augur enters, you draw a card and you lose 1 life.
{2}{B}{B}: Return Clattering Augur from your graveyard to your hand.

Rain of Tears

Hero's Downfall

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Demonic Pact

At the beginning of your upkeep, choose one that hasn't been chosen —
• Demonic Pact deals 4 damage to any target and you gain 4 life.
• Target opponent discards two cards.
• Draw two cards.
• You lose the game.

Vampiric Rites

{1}{B}, Sacrifice a creature: You gain 1 life and draw a card.

Nimblewright Schematic

When Nimblewright Schematic enters or is put into a graveyard from the battlefield, create a 1/1 colorless Construct artifact creature token.

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Village Rites

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

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Ichor Wellspring

When Ichor Wellspring enters or is put into a graveyard from the battlefield, draw a card.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Cult Conscript

Cult Conscript enters tapped.
{1}{B}: Return Cult Conscript from your graveyard to the battlefield. Activate only if a non-Skeleton creature died under your control this turn.

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.)

Break the Ice

Destroy target land that is snow or could produce {C}.
Overload {4}{B}{B} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Elderfang Disciple

When Elderfang Disciple enters, each opponent discards a card.

Liliana's Triumph

Each opponent sacrifices a creature of their choice. If you control a Liliana planeswalker, each opponent also discards a card.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Feed the Swarm

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

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Dreadhound

When Dreadhound enters, mill three cards. (Put the top three cards of your library into your graveyard.)
Whenever a creature dies or a creature card is put into a graveyard from a library, each opponent loses 1 life.

Reassembling Skeleton

{1}{B}: Return Reassembling Skeleton from your graveyard to the battlefield tapped.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Servo Schematic

When Servo Schematic enters or is put into a graveyard from the battlefield, create a 1/1 colorless Servo artifact creature token.

Rancid Earth

Destroy target land.
Threshold — If seven or more cards are in your graveyard, instead destroy that land and Rancid Earth deals 1 damage to each creature and each player.

Nested Shambler

When Nested Shambler dies, create X tapped 1/1 green Squirrel creature tokens, where X is Nested Shambler's power.

Prized Statue

When Prized Statue enters or is put into a graveyard from the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")