Doomsday Excruciator

Flying
When this creature enters, if it was cast, each player exiles all but the bottom six cards of their library face down.
At the beginning of your upkeep, draw a card.

Inner Demon

Enchant creature
Enchanted creature gets +2/+2, has flying, and is a Demon in addition to its other types.
When this Aura enters, all non-Demon creatures get -2/-2 until end of turn.

Mountain

Gateway Plaza

This land enters tapped.
When this land enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Swamp

Ganax, Astral Hunter

Flying
Whenever Ganax or another Dragon you control enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Choose a Background (You can have a Background as a second commander.)

Tibalt's Rager

When this creature dies, it deals 1 damage to any target.
{1}{R}: This creature gets +2/+0 until end of turn.

Fear of Burning Alive

When this creature enters, it deals 4 damage to each opponent.
Delirium — Whenever a source you control deals noncombat damage to an opponent, if there are four or more card types among cards in your graveyard, this creature deals that amount of damage to target creature that player controls.

Jaya's Greeting

Jaya's Greeting deals 3 damage to target creature. Scry 1.

The Creation of Avacyn

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Search your library for a card, exile it face down, then shuffle.
II — Turn the exiled card face up. If it's a creature card, you lose life equal to its mana value.
III — You may put the exiled card onto the battlefield if it's a creature card. If you don't put it onto the battlefield, put it into its owner's hand.

Parasitic Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, its controller loses 2 life and you gain 2 life.

Charcoal Diamond

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

Guildsworn Prowler

Deathtouch
When this creature dies, if it wasn't blocking, draw a card.

Stensia Masquerade

Attacking creatures you control have first strike.
Whenever a Vampire you control deals combat damage to a player, put a +1/+1 counter on it.
Madness {2}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Entropic Cloud

Creatures you control gain deathtouch until end of turn. (Then exile this card. You may cast the creature later from exile.)

Topaz Dragon

Topaz Dragon // Entropic Cloud

Devils' Playground

Create four 1/1 red Devil creature tokens. They have "When this token dies, it deals 1 damage to any target."

Lash of the Balrog

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

Cast Down

Demonic Stench

Each creature that blocked this turn gets -1/-1 until end of turn. (Then exile this card. You may cast the creature later from exile.)

Hezrou

Whenever one or more creatures you control become blocked, each blocking creature gets -1/-1 until end of turn.

Hezrou // Demonic Stench

Atrocious Experiment

Target player mills two cards, draws two cards, and loses 2 life. (To mill a card, a player puts the top card of their library into their graveyard.)

Nemesis Phoenix

Flying
{2}{R}: Return this card from your graveyard to the battlefield tapped and attacking. Activate only during the declare attackers step and only if you're attacking two or more opponents.

Raphael, Fiendish Savior

Flying
Other Demons, Devils, Imps, and Tieflings you control get +1/+1 and have lifelink.
At the beginning of each end step, if a creature card was put into your graveyard from anywhere this turn, create a 1/1 red Devil creature token with "When this token dies, it deals 1 damage to any target."

Sorin's Thirst

Sorin's Thirst deals 2 damage to target creature and you gain 2 life.

Necropolis Fiend

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Flying
{X}, {T}, Exile X cards from your graveyard: Target creature gets -X/-X until end of turn.

Lethal Throwdown

As an additional cost to cast this spell, sacrifice a creature or sacrifice a modified creature. (Equipment, Auras you control, and counters are modifications.)
Destroy target creature or planeswalker. If the modified creature was sacrificed, draw a card.

Demonic Ruckus

Enchant creature
Enchanted creature gets +1/+1 and has menace and trample.
When this Aura is put into a graveyard from the battlefield, draw a card.
Plot {R} (You may pay {R} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Gut, True Soul Zealot

Whenever you attack, you may sacrifice another creature or an artifact. If you do, create a 4/1 black Skeleton creature token with menace that's tapped and attacking. (It can't be blocked except by two or more creatures.)
Choose a Background (You can have a Background as a second commander.)

Mahadi, Emporium Master

At the beginning of your end step, create a Treasure token for each creature that died this turn. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Soul Separator

{5}, {T}, Sacrifice this artifact: Exile target creature card from your graveyard. Create a token that's a copy of that card, except it's 1/1, it's a Spirit in addition to its other types, and it has flying. Create a black Zombie creature token with power equal to that card's power and toughness equal to that card's toughness.

Shiny Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Plaguecrafter

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

Caves of Chaos Adventurer

Trample
When this creature enters, you take the initiative.
Whenever this creature attacks, exile the top card of your library. If you've completed a dungeon, you may play that card this turn without paying its mana cost. Otherwise, you may play that card this turn.

Ominous Cemetery

{T}: Add {C}.
{5}, {T}, Exile this land: Target creature's owner shuffles it into their library.

Vrock

Flying
Toxic Spores — At the beginning of your end step, if a permanent you controlled left the battlefield this turn, each opponent loses 3 life.

Geode Golem

Trample
Whenever this creature deals combat damage to a player, you may cast your commander from the command zone without paying its mana cost. (You still pay any additional costs.)

Fire Diamond

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

Infernal Captor

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, gain control of target artifact or creature until end of turn. Untap that permanent. It gains haste until end of turn.

Ambition's Cost

You draw three cards and you lose 3 life.

Miasma Demon

Flying
When this creature enters, you may discard any number of cards. When you do, up to that many target creatures each get -2/-2 until end of turn.

Infuriate

Target creature gets +3/+2 until end of turn.

Vicious Rumors

Vicious Rumors deals 1 damage to each opponent. Each opponent discards a card, then mills a card. You gain 1 life.

Pilfer

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.

Demonic Covenant

Whenever one or more Demons you control attack a player, you draw a card and lose 1 life.
At the beginning of your end step, create a 5/5 black Demon creature token with flying, then mill two cards. If two cards that share all their card types were milled this way, sacrifice this enchantment.

Infernal Vessel

When this creature dies, if it wasn't a Demon, return it to the battlefield under its owner's control with two +1/+1 counters on it. It's a Demon in addition to its other types.

Murder

Master of the Feast

Flying
At the beginning of your upkeep, each opponent draws a card.

Shock

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Popular Entertainer

Commander creatures you own have "Whenever one or more creatures you control deal combat damage to a player, goad target creature that player controls." (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

The Speed Demon

Flying, trample
Start your engines! (If you have no speed, it starts at 1. It increases once on each of your turns when an opponent loses life. Max speed is 4.)
At the beginning of your end step, you draw X cards and lose X life, where X is your speed.

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.

Skewer the Critics

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Skewer the Critics deals 3 damage to any target.

Bloodboil Sorcerer

When this creature enters, you take the initiative.
Crown of Madness — {1}{R}, Sacrifice an artifact or creature: Goad target creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Charmbreaker Devils

At the beginning of your upkeep, return an instant or sorcery card at random from your graveyard to your hand.
Whenever you cast an instant or sorcery spell, this creature gets +4/+0 until end of turn.

Genasi Enforcers

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
{1}{R}: Creatures you control named Genasi Enforcers get +1/+0 until end of turn.

Demonic Rising

At the beginning of your end step, if you control exactly one creature, create a 5/5 black Demon creature token with flying.

Bloodfell Caves

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {R}.

Summon Undead

You may mill three cards. Then return a creature card from your graveyard to the battlefield. (To mill a card, put the top card of your library into your graveyard.)

Nefarious Imp

Flying
Whenever one or more permanents you control leave the battlefield, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Tiamat's Fanatics

Haste
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Spark Reaper

{3}, Sacrifice a creature or planeswalker: You gain 1 life and draw a card.

Viconia, Drow Apostate

At the beginning of your upkeep, if there are four or more creature cards in your graveyard, return a creature card at random from your graveyard to your hand.
Choose a Background (You can have a Background as a second commander.)

Desecration Demon

Flying
At the beginning of each combat, any opponent may sacrifice a creature of their choice. If a player does, tap this creature and put a +1/+1 counter on it.

Decanter of Endless Water

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

Bonecaller Cleric

{3}{B}, Sacrifice this creature: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

Terminal Agony

Destroy target creature.
Madness {B}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Temple of Malice

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {B} or {R}.

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.)

Bedlam Reveler

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, discard your hand, then draw three cards.

Explosive Crystal

Explosive Crystal deals 4 damage divided as you choose among any number of targets. (Then exile this card. You may cast the creature later from exile.)

Amethyst Dragon

Amethyst Dragon // Explosive Crystal

Rug of Smothering

Flying
Whenever a player casts a spell, they lose 1 life for each spell they've cast this turn.