Drown in Ichor

Target creature gets -4/-4 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Ruinous Ultimatum

Destroy all nonland permanents your opponents control.

Plains

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Offer Immortality

Target creature gains deathtouch and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Humble Defector

{T}: Draw two cards. Target opponent gains control of Humble Defector. Activate only during your turn.

Hunter's Blowgun

Equipped creature gets +1/+1.
Equipped creature has deathtouch during your turn. Otherwise, it has reach.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Hidden Blade

Flash
When Hidden Blade enters, attach it to target creature you control. If that creature is an Assassin, it gains deathtouch until end of turn.
Equipped creature gets +1/+0 and has first strike.
Equip {2}

Dragonskull Summit

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Rune of Mortality

Enchant permanent
When Rune of Mortality enters, draw a card.
As long as enchanted permanent is a creature, it has deathtouch.
As long as enchanted permanent is an Equipment, it has "Equipped creature has deathtouch."

Drumbellower

Flying
Untap all creatures you control during each other player's untap step.

Savai Triome

({T}: Add {R}, {W}, or {B}.)
Savai Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Magda, the Hoardmaster

Whenever you commit a crime, create a tapped Treasure token. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)
Sacrifice three Treasures: Create a 4/4 red Scorpion Dragon creature token with flying and haste. Activate only as a sorcery.

Arcane Signet

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

Vault of Champions

Vault of Champions enters tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

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.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters, you may pay 2 life. If you don't, it enters tapped.

Minthara, Merciless Soul

Minthara has ward {X}, where X is the number of experience counters you have.
At the beginning of your end step, if a permanent you controlled left the battlefield this turn, you get an experience counter.
Creatures you control get +1/+0 for each experience counter you have.

Patriar's Seal

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

Forbidden Orchard

{T}: Add one mana of any color.
Whenever you tap Forbidden Orchard for mana, target opponent creates a 1/1 colorless Spirit creature token.

Vraska, Betrayal's Sting

Compleated ({B/P} can be paid with {B} or 2 life. If life was paid, this planeswalker enters with two fewer loyalty counters.)
0: You draw a card and you lose 1 life. Proliferate.
−2: Target creature becomes a Treasure artifact with "{T}, Sacrifice this artifact: Add one mana of any color" and loses all other card types and abilities.
−9: If target player has fewer than nine poison counters, they get a number of poison counters equal to the difference.

Rogue's Passage

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

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Harvester of Souls

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another nontoken creature dies, you may draw a card.

Falthis, Shadowcat Familiar

Commanders you control have menace and deathtouch.
Partner (You can have two commanders if both have partner.)

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}

Mother of Runes

{T}: Target creature you control gains protection from the color of your choice until end of turn.

Rakdos Signet

You Are Already Dead

Destroy target creature that was dealt damage this turn.
Draw a card.

Generous Gift

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

Phyrexian Arena

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

At Knifepoint

During your turn, outlaws you control have first strike. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)
Whenever you commit a crime, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery." This ability triggers only once each turn.

Mountain

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.)

Revel in Riches

Whenever a creature an opponent controls dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
At the beginning of your upkeep, if you control ten or more Treasures, you win the game.

White Plume Adventurer

When White Plume Adventurer enters, you take the initiative.
At the beginning of each opponent's upkeep, untap a creature you control. If you've completed a dungeon, untap all creatures you control instead.

Vorpal Sword

Equipped creature gets +2/+0 and has deathtouch.
{5}{B}{B}{B}: Until end of turn, Vorpal Sword gains "Whenever equipped creature deals combat damage to a player, that player loses the game."
Equip {B}{B}

Lae'zel, Vlaakith's Champion

If you would put one or more counters on a creature or planeswalker you control or on yourself, put that many plus one of each of those kinds of counters on that permanent or player instead.
Choose a Background (You can have a Background as a second commander.)

Clifftop Retreat

Clifftop Retreat enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Quietus Spike

Equipped creature has deathtouch.
Whenever equipped creature deals combat damage to a player, that player loses half their life, rounded up.
Equip {3}

Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Daxos the Returned

Whenever you cast an enchantment spell, you get an experience counter.
{1}{W}{B}: Create a white and black Spirit enchantment creature token. It has "This creature's power and toughness are each equal to the number of experience counters you have."

Unfinished Business

Return target creature card from your graveyard to the battlefield, then return up to two target Aura and/or Equipment cards from your graveyard to the battlefield attached to that creature. (If the Auras can't enchant that creature, they remain in your graveyard.)

Otharri, Suns' Glory

Flying, lifelink, haste
Whenever Otharri, Suns' Glory attacks, you get an experience counter. Then create a 2/2 red Rebel creature token that's tapped and attacking for each experience counter you have.
{2}{R}{W}, Tap an untapped Rebel you control: Return Otharri from your graveyard to the battlefield tapped.

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters, you may pay 2 life. If you don't, it enters tapped.

Gorgon Flail

Equipped creature gets +1/+1 and has deathtouch. (Any amount of damage it deals to a creature is enough to destroy that creature.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

Mythos of Snapdax

Each player chooses an artifact, a creature, an enchantment, and a planeswalker from among the nonland permanents they control, then sacrifices the rest. If {B}{R} was spent to cast this spell, you choose the permanents for each player instead.

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Goblin Sharpshooter

Goblin Sharpshooter doesn't untap during your untap step.
Whenever a creature dies, untap Goblin Sharpshooter.
{T}: Goblin Sharpshooter deals 1 damage to any target.

Boros Signet

Swamp

Sting, the Glinting Dagger

Equipped creature gets +1/+1 and has haste.
At the beginning of each combat, untap equipped creature.
Equipped creature has first strike as long as it's blocking or blocked by a Goblin or Orc.
Equip {2}

Nomad Outpost

Nomad Outpost enters tapped.
{T}: Add {R}, {W}, or {B}.

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.)

Sun Titan

Vigilance
Whenever Sun Titan enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Spectator Seating

Spectator Seating enters tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Fighter Class

(Gain the next level as a sorcery to add its ability.)
When Fighter Class enters, search your library for an Equipment card, reveal it, put it into your hand, then shuffle.
{1}{R}{W}: Level 2
Equip abilities you activate cost {2} less to activate.
{3}{R}{W}: Level 3
Whenever a creature you control attacks, up to one target creature blocks it this combat if able.

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters tapped unless you control two or more basic lands.

Taii Wakeen, Perfect Shot

Whenever a source you control deals noncombat damage to a creature equal to that creature's toughness, draw a card.
{X}, {T}: If a source you control would deal noncombat damage to a permanent or player this turn, it deals that much damage plus X instead.

Gorgon's Head

Equipped creature has deathtouch.
Equip {2}

Despark

Exile target permanent with mana value 4 or greater.

Gift of Doom

Enchant creature
Enchanted creature has deathtouch and indestructible.
Morph—Sacrifice another creature. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
As Gift of Doom is turned face up, you may attach it to a creature.

Aspect of Gorgon

Enchant creature
Enchanted creature gets +1/+3 and has deathtouch. (Any amount of damage it deals to a creature is enough to destroy it.)

Slaughter Specialist

When Slaughter Specialist enters, each opponent creates a 1/1 white Human creature token.
Whenever a creature an opponent controls dies, put a +1/+1 counter on Slaughter Specialist.

Kalemne, Disciple of Iroas

Double strike, vigilance
Whenever you cast a creature spell with mana value 5 or greater, you get an experience counter.
Kalemne, Disciple of Iroas gets +1/+1 for each experience counter you have.

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. Caves of Koilos deals 1 damage to you.

Bojuka Bog

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

Kelsien, the Plague

Vigilance, haste
Kelsien, the Plague gets +1/+1 for each experience counter you have.
{T}: Kelsien deals 1 damage to target creature you don't control. When that creature dies this turn, you get an experience counter.

Open the Armory

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Void Beckoner

Deathtouch
Cycling {2}{B} ({2}{B}, Discard this card: Draw a card.)
When you cycle Void Beckoner, put a deathtouch counter on target creature you control.

Orzhov Signet

Luxury Suite

Luxury Suite enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Sol Ring

Isolated Chapel

Isolated Chapel enters tapped unless you control a Plains or a Swamp.
{T}: Add {W} or {B}.

General's Enforcer

Legendary Humans you control have indestructible.
{2}{W}{B}: Exile target card from a graveyard. If it was a creature card, create a 1/1 white Human Soldier creature token.

Vault of the Archangel

{T}: Add {C}.
{2}{W}{B}, {T}: Creatures you control gain deathtouch and lifelink until end of turn.

Archetype of Finality

Creatures you control have deathtouch.
Creatures your opponents control lose deathtouch and can't have or gain deathtouch.

Fracture

Destroy target artifact, enchantment, or planeswalker.

Magewright's Stone

{1}, {T}: Untap target creature that has an activated ability with {T} in its cost.

Crackling Doom

Crackling Doom deals 2 damage to each opponent. Each opponent sacrifices a creature with the greatest power among creatures that player controls.

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Painful Truths

Converge — You draw X cards and you lose X life, where X is the number of colors of mana spent to cast this spell.

Mari, the Killing Quill

Whenever a creature an opponent controls dies, exile it with a hit counter on it.
Assassins, Mercenaries, and Rogues you control have deathtouch and "Whenever this creature deals combat damage to a player, you may remove a hit counter from a card that player owns in exile. If you do, draw a card and create two Treasure tokens."

Mirrodin Avenged

Evolving Wilds

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

Morbid Opportunist

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

Termination Facilitator

{T}: Put a bounty counter on target creature or planeswalker. Activate only as a sorcery.
Whenever a creature or planeswalker an opponent controls with a bounty counter on it is dealt damage, destroy it.