Sarevok, Deathbringer

At the beginning of each player's end step, if no permanents left the battlefield this turn, that player loses X life, where X is Sarevok's power.
Choose a Background (You can have a Background as a second commander.)

Morphic Pool

This land enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Essence Capture

Counter target creature spell. Put a +1/+1 counter on up to one target creature you control.

Grim Haruspex

Morph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
Whenever another nontoken creature you control dies, draw a card.

Their Number Is Legion

Create X tapped 2/2 black Necron Warrior artifact creature tokens, then you gain life equal to the number of artifacts you control. Exile Their Number Is Legion.
You may cast this card from your graveyard.

Anchor to the Aether

Put target creature on top of its owner's library. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Multiple Choice

If X is 1, scry 1, then draw a card.
If X is 2, you may choose a player. They return a creature they control to its owner's hand.
If X is 3, create a 4/4 blue and red Elemental creature token.
If X is 4 or more, do all of the above.

Haunt the Network

Choose target opponent. Create two 1/1 colorless Thopter artifact creature tokens with flying. Then the chosen player loses X life and you gain X life, where X is the number of artifacts you control.

Blood Artist

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

Chrome Host Seedshark

Flying
Whenever you cast a noncreature spell, incubate X, where X is that spell's mana value. (Create an Incubator token with X +1/+1 counters on it and "{2}: Transform this token." It transforms into a 0/0 Phyrexian artifact creature.)

Spinal Embrace

Cast this spell only during combat.
Untap target creature you don't control and gain control of it. It gains haste until end of turn. At the beginning of the next end step, sacrifice it. If you do, you gain life equal to its toughness.

Junk Diver

Flying
When this creature dies, return another target artifact card from your graveyard to your hand.

Falkenrath Noble

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

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.

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.)

Sengir Nosferatu

Flying
{1}{B}, Exile this creature: Create a 1/2 black Bat creature token with flying. It has "{1}{B}, Sacrifice this token: Return an exiled card named Sengir Nosferatu to the battlefield under its owner's control."

Titan Hunter

At the beginning of each player's end step, if no creatures died this turn, this creature deals 4 damage to that player.
{1}{B}, Sacrifice a creature: You gain 4 life.

Clan Crafter

Commander creatures you own have "{2}, Sacrifice an artifact: Put a +1/+1 counter on this creature and draw a card."

Surgical Skullbomb

{1}, Sacrifice this artifact: Draw a card.
{2}{U}, Sacrifice this artifact: Return target creature to its owner's hand. Draw a card. Activate only as a sorcery.

Obsessive Stitcher

{T}: Draw a card, then discard a card.
{2}{U}{B}, {T}, Sacrifice this creature: Return target creature card from your graveyard to the battlefield.

Beamsaw Prospector

When this creature dies, create a Lander token. (It's an artifact with "{2}, {T}, Sacrifice this token: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.")

Endrek Sahr, Master Breeder

Whenever you cast a creature spell, create X 1/1 black Thrull creature tokens, where X is that spell's mana value.
When you control seven or more Thrulls, sacrifice Endrek Sahr.

Soured Springs

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {U} or {B}.

Geistwave

Return target nonland permanent to its owner's hand. If you controlled that permanent, draw a card.

Academy Manufactor

If you would create a Clue, Food, or Treasure token, instead create one of each.

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.)

Darksteel Pendant

Indestructible (Effects that say "destroy" don't destroy this artifact.)
{1}, {T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Vat of Rebirth

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

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Treasure Keeper

When this creature dies, reveal cards from the top of your library until you reveal a nonland card with mana value 3 or less. You may cast that card without paying its mana cost. Put all revealed cards not cast this way on the bottom of your library in a random order.

Mystic Forge

You may look at the top card of your library any time.
You may cast artifact spells and colorless spells from the top of your library.
{T}, Pay 1 life: Exile the top card of your library.

Divert Disaster

Counter target spell unless its controller pays {2}. If they do, you create a Lander token. (It's an artifact with "{2}, {T}, Sacrifice this token: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.")

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."

Fabled Passage

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Goremand

As an additional cost to cast this spell, sacrifice a creature.
Flying
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
When this creature enters, each opponent sacrifices a creature.

Midnight Reaper

Whenever a nontoken creature you control dies, this creature deals 1 damage to you and you draw a card.

Magebane Armor

Equipped creature gets +2/+4 and loses flying.
Prevent all noncombat damage that would be dealt to equipped creature.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

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."

Zulaport Cutthroat

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

Jet Medallion

Black spells you cast cost {1} less to cast.

Annihilating Glare

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

Shimmer Myr

Flash
You may cast artifact spells as though they had flash.

Inspiring Statuary

Nonartifact spells you cast have improvise. (Your artifacts can help cast those spells. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Tamiyo's Logbook

{5}{U}, {T}: Draw a card. This ability costs {1} less to activate for each other artifact you control.

Ichor Wellspring

When this artifact enters or is put into a graveyard from the battlefield, draw a card.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Mimic Vat

Imprint — Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with this artifact to its owner's graveyard.
{3}, {T}: Create a token that's a copy of a card exiled with this artifact. It gains haste. Exile it at the beginning of the next end step.

Kaervek, the Spiteful

Efficient Construction

Whenever you cast an artifact spell, create a 1/1 colorless Thopter artifact creature token with flying.

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.")

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Diversion Unit

Flying
{U}, Sacrifice this creature: Counter target instant or sorcery spell unless its controller pays {3}.

Command Tower

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

Plaguecrafter

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

Accursed Marauder

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

Reaper's Talisman

Whenever equipped creature attacks, it gains deathtouch until end of turn.
Whenever equipped creature attacks alone, defending player loses 2 life and you gain 2 life.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

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.

Gaius van Baelsar

When Gaius van Baelsar enters, choose one —
• Each player sacrifices a creature token of their choice.
• Each player sacrifices a nontoken creature of their choice.
• Each player sacrifices an enchantment of their choice.

Nutrient Block

Indestructible (Effects that say "destroy" don't destroy this artifact.)
{2}, {T}, Sacrifice this artifact: You gain 3 life.
When this artifact is put into a graveyard from the battlefield, draw a card.

Novice Dissector

{1}, Sacrifice another creature: Put a +1/+1 counter on target creature. Activate only as a sorcery.

Foundry Inspector

Artifact spells you cast cost {1} less to cast.

Phyrexian Triniform

When this creature dies, create three 3/3 colorless Phyrexian Golem artifact creature tokens.
Encore {12} ({12}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

The Key to the Vault

Whenever equipped creature deals combat damage to a player, look at that many cards from the top of your library. You may exile a nonland card from among them. Put the rest on the bottom of your library in a random order. You may cast the exiled card without paying its mana cost.
Equip {2}{U}

Shambling Ghast

When this creature 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 token: Add one mana of any color.")

Vivisection

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

Lithoform Engine

{2}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy.
{3}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.
{4}, {T}: Copy target permanent spell you control. (The copy becomes a token.)

Sifter of Skulls

Devoid (This card has no color.)
Whenever another nontoken creature you control dies, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this token: Add {C}." ({C} represents colorless mana.)

Traverse Eternity

Draw cards equal to the greatest mana value among historic permanents you control. (Artifacts, legendaries, and Sagas are historic.)

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Vedalken Archmage

Whenever you cast an artifact spell, draw a card.

Spell Swindle

Counter target spell. Create X Treasure tokens, where X is that spell's mana value. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Mephitic Draught

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

Hostage Taker

When this creature enters, exile another target creature or artifact until this creature leaves the battlefield. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Annul

Counter target artifact or enchantment spell.

Sculpting Steel

You may have this artifact enter as a copy of any artifact on the battlefield.

Workshop Assistant

When this creature dies, return another target artifact card from your graveyard to your hand.

Underhanded Designs

Whenever an artifact you control enters, you may pay {1}. If you do, each opponent loses 1 life and you gain 1 life.
{1}{B}, Sacrifice this enchantment: Destroy target creature. Activate only if you control two or more artifacts.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Liliana, Death's Majesty

+1: Create a 2/2 black Zombie creature token. Mill two cards.
−3: Return target creature card from your graveyard to the battlefield. That creature is a black Zombie in addition to its other colors and types.
−7: Destroy all non-Zombie creatures.

Mask of Riddles

Equipped creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
Whenever equipped creature deals combat damage to a player, you may draw a card.
Equip {2}

Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Bushmeat Poacher

{1}, {T}, Sacrifice another creature: You gain life equal to the sacrificed creature's toughness. Draw a card.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Shadowmage Infiltrator

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever this creature deals combat damage to a player, you may draw a card.