Dictate of Erebos

Flash
Whenever a creature you control dies, each opponent sacrifices a creature.

Swiftfoot Boots

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

Dark Ritual

Liliana's Standard Bearer

Flash
When Liliana's Standard Bearer enters the battlefield, draw X cards, where X is the number of creatures that died under your control this turn.

Terramorphic Expanse

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

Spark Double

You may have Spark Double enter the battlefield as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Mass Diminish

Until your next turn, creatures target player controls have base power and toughness 1/1.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Undying Malice

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."

Blink of an Eye

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Return target nonland permanent to its owner's hand. If this spell was kicked, draw a card.

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature.

Contagion Engine

When Contagion Engine enters the battlefield, put a -1/-1 counter on each creature target player controls.
{4}, {T}: Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Species Specialist

As Species Specialist enters the battlefield, choose a creature type.
Whenever a creature of the chosen type dies, you may draw a card.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Arcane Signet

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

Command Tower

Evolving Wilds

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

Bad River

Bad River enters the battlefield tapped.
{T}, Sacrifice Bad River: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

The Meathook Massacre

When The Meathook Massacre enters the battlefield, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Island

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Sol Ring

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Feign Death

Negate

Stinging Study

You draw X cards and you lose X life, where X is the mana value of a commander you own on the battlefield or in the command zone.

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Planar Void

Whenever another card is put into a graveyard from anywhere, exile that card.

Mind Stone

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

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters the battlefield tapped unless you control three or more other Islands.
When Mystic Sanctuary enters the battlefield untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Toxrill, the Corrosive

At the beginning of each end step, put a slime counter on each creature you don't control.
Creatures you don't control get -1/-1 for each slime counter on them.
Whenever a creature you don't control with a slime counter on it dies, create a 1/1 black Slug creature token.
{U}{B}, Sacrifice a Slug: Draw a card.

Massacre Girl, Known Killer

Menace
Creatures you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent controls dies, if its toughness was less than 1, draw a card.

Black Market

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

Encroaching Wastes

{T}: Add {C}.
{4}, {T}, Sacrifice Encroaching Wastes: Destroy target nonbasic land.

Sudden Spoiling

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Until end of turn, creatures target player controls lose all abilities and have base power and toughness 0/2.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Infernal Grasp

Destroy target creature. You lose 2 life.

Deathgreeter

Whenever another creature dies, you may gain 1 life.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter the battlefield as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Azcanta, the Sunken Ruin

(Transforms from Search for Azcanta.)
{T}: Add {U}.
{2}{U}, {T}: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Search for Azcanta

At the beginning of your upkeep, surveil 1. Then if you have seven or more cards in your graveyard, you may transform Search for Azcanta. (Look at the top card of your library. You may put that card into your graveyard.)

Search for Azcanta // Azcanta, the Sunken Ruin

Damnation

Destroy all creatures. They can't be regenerated.

Sunken Ruins

{T}: Add {C}.
{U/B}, {T}: Add {U}{U}, {U}{B}, or {B}{B}.

Bojuka Bog

Bojuka Bog enters the battlefield tapped.
When Bojuka Bog enters the battlefield, exile target player's graveyard.
{T}: Add {B}.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Sludge Monster

Whenever Sludge Monster enters the battlefield or attacks, put a slime counter on up to one other target creature.
Non-Horror creatures with slime counters on them lose all abilities and have base power and toughness 2/2.

Swamp

Commander's Sphere

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

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Malakir Mire

Malakir Mire enters the battlefield tapped.
{T}: Add {B}.

Malakir Rebirth

Choose target creature. You lose 2 life. Until end of turn, that creature gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Malakir Rebirth // Malakir Mire

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.)

Inexorable Tide

Whenever you cast a spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Ayara, First of Locthwain

Whenever Ayara, First of Locthwain or another black creature enters the battlefield under your control, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Dimir Signet

Feed the Swarm

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

Counterspell

Shipwreck Marsh

Shipwreck Marsh enters the battlefield tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Dissipate

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Sakashima the Impostor

You may have Sakashima the Impostor enter the battlefield as a copy of any creature on the battlefield, except its name is Sakashima the Impostor, it's legendary in addition to its other types, and it has "{2}{U}{U}: Return this creature to its owner's hand at the beginning of the next end step."

Zulaport Cutthroat

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

Polymorphist's Jest

Until end of turn, each creature target player controls loses all abilities and becomes a blue Frog with base power and toughness 1/1.

Vona's Hunger

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Each opponent sacrifices a creature. If you have the city's blessing, instead each opponent sacrifices half the creatures they control, rounded up.

Countersquall

Counter target noncreature spell. Its controller loses 2 life.

Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Drown in the Loch

Choose one —
• Counter target spell with mana value less than or equal to the number of cards in its controller's graveyard.
• Destroy target creature with mana value less than or equal to the number of cards in its controller's graveyard.

Massacre Wurm

When Massacre Wurm enters the battlefield, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Morphic Pool

Morphic Pool enters the battlefield tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Corpse Augur

When Corpse Augur dies, you draw X cards and you lose X life, where X is the number of creature cards in target player's graveyard.

Pact of the Serpent

Choose a creature type. Target player draws X cards and loses X life, where X is the number of creatures they control of the chosen type.

Flux Channeler

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Darkwater Catacombs

Into the Roil

Vein Ripper

Flying
Ward—Sacrifice a creature.
Whenever a creature dies, target opponent loses 2 life and you gain 2 life.