Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

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.")

Blightbelly Rat

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When Blightbelly Rat dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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 artifact: Add one mana of any color.")

Jeska, Thrice Reborn

Jeska, Thrice Reborn enters with a loyalty counter on her for each time you've cast a commander from the command zone this game.
0: Choose target creature. Until your next turn, if that creature would deal combat damage to one of your opponents, it deals triple that damage to that player instead.
−X: Jeska, Thrice Reborn deals X damage to each of up to three targets.
Jeska, Thrice Reborn can be your commander.
Partner

Seething Song

Settle the Score

Exile target creature. Put two loyalty counters on a planeswalker you control.

Desperate Ritual

Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Pyretic Ritual

Kiki-Jiki, Mirror Breaker

Haste
{T}: Create a token that's a copy of target nonlegendary creature you control, except it has haste. Sacrifice it at the beginning of the next end step.

Mountain

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Blood Pet

Kolaghan's Command

Choose two —
• Return target creature card from your graveyard to your hand.
• Target player discards a card.
• Destroy target artifact.
• Kolaghan's Command deals 2 damage to any target.

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.)

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Solemn Simulacrum

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

Morbid Opportunist

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

Searstep Pathway

Blightstep Pathway

Blightstep Pathway // Searstep Pathway

Ashnod's Altar

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Tevesh Szat, Doom of Fools

+2: Create two 0/1 black Thrull creature tokens.
+1: You may sacrifice another creature or planeswalker. If you do, draw two cards, then draw another card if the sacrificed permanent was a commander.
−10: Gain control of all commanders. Put all commanders from the command zone onto the battlefield under your control.
Tevesh Szat, Doom of Fools can be your commander.
Partner

Skirk Prospector

Orcish Bowmasters

Flash
When Orcish Bowmasters enters and whenever an opponent draws a card except the first one they draw in each of their draw steps, Orcish Bowmasters deals 1 damage to any target. Then amass Orcs 1.

Mayhem Devil

Whenever a player sacrifices a permanent, Mayhem Devil deals 1 damage to any target.

Saw in Half

Destroy target creature. If that creature dies this way, its controller creates two tokens that are copies of that creature, except their power is half that creature's power and their toughness is half that creature's toughness. Round up each time.

Diabolic Intent

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card, put that card into your hand, then shuffle.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Jeska's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Add {R} for each card in target opponent's hand.
• Exile the top three cards of your library. You may play them this turn.

Corrupted Conviction

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

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.

Lagomos, Hand of Hatred

At the beginning of combat on your turn, create a 2/1 red Elemental creature token with trample and haste. Sacrifice it at the beginning of the next end step.
{T}: Search your library for a card, put it into your hand, then shuffle. Activate only if five or more creatures died this turn.

Chandra, Acolyte of Flame

0: Put a loyalty counter on each red planeswalker you control.
0: Create two 1/1 red Elemental creature tokens. They gain haste. Sacrifice them at the beginning of the next end step.
−2: You may cast target instant or sorcery card with mana value 3 or less from your graveyard. If that spell would be put into your graveyard, exile it instead.

Swamp

Kari Zev's Expertise

Gain control of target creature or Vehicle until end of turn. Untap it. It gains haste until end of turn.
You may cast a spell with mana value 2 or less from your hand without paying its mana cost.

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Rakdos Signet

Stitcher's Supplier

When Stitcher's Supplier enters or dies, mill three cards. (Put the top three cards of your library into your graveyard.)

Scheming Symmetry

Choose two target players. Each of them searches their library for a card, then shuffles and puts that card on top.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Plaguecrafter

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

Arcane Signet

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

Mirkwood Bats

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

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Zulaport Cutthroat

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