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.)

Blood Artist

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

Tainted Wood

{T}: Add {C}.
{T}: Add {B} or {G}. Activate only if you control a Swamp.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Reliquary Tower

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

Swamp

Terramorph

Search your library for a basic land card, put it onto the battlefield, then shuffle.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Illusionist's Bracers

Whenever an ability of equipped creature is activated, if it isn't a mana ability, copy that ability. You may choose new targets for the copy.
Equip {3}

Ichor Wellspring

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

Sol Ring

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.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Patriar's Seal

{T}: Add one mana of any color.
{1}, {T}: Untap target legendary creature you control.

Thornbite Staff

Equipped creature has "{2}, {T}: This creature deals 1 damage to any target" and "Whenever a creature dies, untap this creature."
Whenever a Shaman creature enters, you may attach Thornbite Staff to it.
Equip {4}

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.")

Mycosynth Wellspring

When Mycosynth Wellspring enters or is put into a graveyard from the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Mephitic Draught

When Mephitic Draught enters or is put into a graveyard from the battlefield, you draw a card and you lose 1 life.

Honest Rutstein

When Honest Rutstein enters, return target creature card from your graveyard to your hand.
Creature spells you cast cost {1} less to cast.

Conduit of Worlds

You may play lands from your graveyard.
{T}: Choose target nonland permanent card in your graveyard. If you haven't cast a spell this turn, you may cast that card. If you do, you can't cast additional spells this turn. Activate only as a sorcery.

Meren of Clan Nel Toth

Whenever another creature you control dies, you get an experience counter.
At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.

Bone Offering

Create a tapped 4/1 black Skeleton creature token with menace. (Then exile this card. You may cast the artifact later from exile.)

Altar of Bhaal

{2}{B}, {T}, Exile a creature you control: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

Altar of Bhaal // Bone Offering

Vat of Rebirth

Whenever another artifact or creature you control is put into a graveyard from the battlefield, put an oil counter on Vat of Rebirth.
{2}{B}, {T}, Remove four oil counters from Vat of Rebirth: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

The Mycotyrant

Trample
The Mycotyrant's power and toughness are each equal to the number of creatures you control that are Fungi and/or Saprolings.
At the beginning of your end step, create X 1/1 black Fungus creature tokens with "This creature can't block," where X is the number of times you descended this turn. (You descend each time a permanent card is put into your graveyard from anywhere.)

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.

Cavalier of Night

Lifelink
When Cavalier of Night enters, you may sacrifice another creature. When you do, destroy target creature an opponent controls.
When Cavalier of Night dies, return target creature card with mana value 3 or less from your graveyard to the battlefield.

Servo Schematic

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

Desecrated Tomb

Whenever one or more creature cards leave your graveyard, create a 1/1 black Bat creature token with flying.

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."

Body Snatcher

When Body Snatcher enters, exile it unless you discard a creature card.
When Body Snatcher dies, exile it and return target creature card from your graveyard to the battlefield.

Cathodion

Thousand-Year Elixir

You may activate abilities of creatures you control as though those creatures had haste.
{1}, {T}: Untap target creature.

Compy Swarm

At the beginning of your end step, if a creature died this turn, create a tapped token that's a copy of Compy Swarm.

Feral Prowler

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.)

Dead Reckoning

You may put target creature card from your graveyard on top of your library. If you do, Dead Reckoning deals damage equal to that card's power to target creature.

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Crawling Sensation

At the beginning of your upkeep, you may mill two cards. (You may put the top two cards of your library into your graveyard.)
Whenever one or more land cards are put into your graveyard from anywhere for the first time each turn, create a 1/1 green Insect creature token.

Squirming Emergence

Fathomless descent — Return to the battlefield target nonland permanent card in your graveyard with mana value less than or equal to the number of permanent cards in your graveyard.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Mortuary

Whenever a creature is put into your graveyard from the battlefield, put that card on top of your library.

Exquisite Blood

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

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Cloakwood Hermit

Commander creatures you own have "At the beginning of your end step, if a creature card was put into your graveyard from anywhere this turn, create two tapped 1/1 green Squirrel creature tokens."

Nimblewright Schematic

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

Undergrowth Stadium

Undergrowth Stadium enters tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Clone Shell

Imprint — When Clone Shell enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom of your library in any order.
When Clone Shell dies, turn the exiled card face up. If it's a creature card, put it onto the battlefield under your control.

Poison-Tip Archer

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another creature dies, each opponent loses 1 life.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Forest

Skyfisher Spider

Reach
When Skyfisher Spider enters, you may sacrifice another creature. When you do, destroy target nonland permanent.
When Skyfisher Spider dies, you may gain 1 life for each creature card in your graveyard. If you do, exile Skyfisher Spider from your graveyard.

Golgari Rot Farm

Golgari Rot Farm enters tapped.
When Golgari Rot Farm enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Arcane Signet

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

Filigree Familiar

When Filigree Familiar enters, you gain 2 life.
When Filigree Familiar dies, draw a card.

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.

Genesis

At the beginning of your upkeep, if Genesis is in your graveyard, you may pay {2}{G}. If you do, return target creature card from your graveyard to your hand.

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Chitterspitter

At the beginning of your upkeep, you may sacrifice a token. If you do, put an acorn counter on Chitterspitter.
Squirrels you control get +1/+1 for each acorn counter on Chitterspitter.
{G}, {T}: Create a 1/1 green Squirrel creature token.

Relic Vial

{2}, {T}, Sacrifice a creature: Draw a card.
As long as you control a Cleric, Relic Vial has "Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life."

Dutiful Attendant

When Dutiful Attendant dies, return another target creature card from your graveyard to your hand.

Elves of Deep Shadow

{T}: Add {B}. Elves of Deep Shadow deals 1 damage to you.

Crawling Infestation

At the beginning of your upkeep, you may mill two cards. (You may put the top two cards of your library into your graveyard.)
Whenever one or more creature cards are put into your graveyard from anywhere during your turn, create a 1/1 green Insect creature token. This ability triggers only once each turn.

Tormod, the Desecrator

Whenever one or more cards leave your graveyard, create a tapped 2/2 black Zombie creature token.
Partner (You can have two commanders if both have partner.)

Lightning Greaves

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

Skeleton Crew

Each other creature you control that's a Skeleton or Pirate gets +1/+1.
Whenever one or more creature cards leave your graveyard, create a 2/2 black Skeleton Pirate creature token. (This ability triggers only from the battlefield.)
{5}{B}: Return Skeleton Crew from your graveyard to the battlefield tapped.

Doomed Dissenter

When Doomed Dissenter dies, create a 2/2 black Zombie creature token.

Seeker of Skybreak

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle Elixir of Immortality and your graveyard into their owner's library.

Barishi

When Barishi dies, exile Barishi, then shuffle all creature cards from your graveyard into your library.

Kagha, Shadow Archdruid

Whenever Kagha, Shadow Archdruid attacks, it gains deathtouch until end of turn. Mill two cards. (Put the top two cards of your library into your graveyard.)
Once during each of your turns, you may play a land or cast a permanent spell from among cards in your graveyard that were put there from your library this turn.

Zulaport Cutthroat

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

Instill Energy

Enchant creature
Enchanted creature can attack as though it had haste.
{0}: Untap enchanted creature. Activate only during your turn and only once each turn.

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Morbid Opportunist

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

Cavalier of Thorns

Reach
When Cavalier of Thorns enters, reveal the top five cards of your library. Put a land card from among them onto the battlefield and the rest into your graveyard.
When Cavalier of Thorns dies, you may exile it. If you do, put another target card from your graveyard on top of your library.

Command Tower

Pitiless Plunderer

Whenever another creature you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Arcbound Reclaimer

Remove a +1/+1 counter from Arcbound Reclaimer: Put target artifact card from your graveyard on top of your library.
Modular 2 (This creature enters with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Insidious Roots

Creature tokens you control have "{T}: Add one mana of any color."
Whenever one or more creature cards leave your graveyard, create a 0/1 green Plant creature token, then put a +1/+1 counter on each Plant you control.

Dread Whispers

You draw a card and you lose 1 life. (Then exile this card. You may cast the creature later from exile.)

Mosswood Dreadknight

Trample
When Mosswood Dreadknight dies, you may cast it from your graveyard as an Adventure until the end of your next turn.

Mosswood Dreadknight // Dread Whispers

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Black Market

Whenever a creature dies, put a charge counter on Black Market.
At the beginning of your first main phase, add {B} for each charge counter on Black Market.