Urborg, Tomb of Yawgmoth

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

Order of Succession

Choose left or right. Starting with you and proceeding in the chosen direction, each player chooses a creature controlled by the next player in that direction. Each player gains control of the creature they chose.

Curse of Verbosity

Enchant player
Whenever enchanted player is attacked, you draw a card. Each opponent attacking that player does the same.

Illusionist's Gambit

Cast this spell only during the declare blockers step on an opponent's turn.
Remove all attacking creatures from combat and untap them. After this phase, there is an additional combat phase. Each of those creatures attacks that combat if able. They can't attack you or planeswalkers you control that combat.

Gang Up

Assist (Another player can pay up to {X} of this spell's cost. You choose the value of X.)
Destroy target creature with power X or less.

Fatespinner

At the beginning of each opponent's upkeep, that player chooses draw step, main phase, or combat phase. The player skips each instance of the chosen step or phase this turn.

Perplexing Chimera

Whenever an opponent casts a spell, you may exchange control of Perplexing Chimera and that spell. If you do, you may choose new targets for the spell. (If the spell becomes a permanent, you control that permanent.)

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Game Plan

Assist (Another player can pay up to {5} of this spell's cost.)
Each player shuffles their hand and graveyard into their library, then draws seven cards. Exile Game Plan.

Tempt with Immortality

Tempting offer — Return a creature card from your graveyard to the battlefield. Each opponent may return a creature card from their graveyard to the battlefield. For each opponent who does, return a creature card from your graveyard to the battlefield.

Bloodthirsty Blade

Equipped creature gets +2/+0 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
{1}: Attach Bloodthirsty Blade to target creature an opponent controls. Activate only as a sorcery.

Mind's Dilation

Whenever an opponent casts their first spell each turn, that player exiles the top card of their library. If it's a nonland card, you may cast it without paying its mana cost.

Out of Bounds

Assist (Another player can pay up to {3} of this spell's cost.)
Counter target spell.

Eye of Doom

When Eye of Doom enters, each player chooses a nonland permanent and puts a doom counter on it.
{2}, {T}, Sacrifice Eye of Doom: Destroy each permanent with a doom counter on it.

Fetid Pools

({T}: Add {U} or {B}.)
Fetid Pools enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Aetherspouts

For each attacking creature, its owner puts it on their choice of the top or bottom of their library.

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Fraying Omnipotence

Each player loses half their life, then discards half the cards in their hand, then sacrifices half the creatures they control of their choice. Round up each time.

Exotic Orchard

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

Dimir Signet

Manifold Insights

Reveal the top ten cards of your library. Starting with the next opponent in turn order, each opponent chooses a different nonland card from among them. Put the chosen cards into your hand and the rest on the bottom of your library in a random order.

Wishclaw Talisman

This artifact enters with three wish counters on it.
{1}, {T}, Remove a wish counter from this artifact: Search your library for a card, put it into your hand, then shuffle. An opponent gains control of this artifact. Activate only during your turn.

Crown of Doom

Whenever a creature attacks you or a planeswalker you control, it gets +2/+0 until end of turn.
{2}: Target player other than Crown of Doom's owner gains control of it. Activate only during your turn.

Evil Twin

You may have Evil Twin enter as a copy of any creature on the battlefield, except it has "{U}{B}, {T}: Destroy target creature with the same name as this creature."

Command Tower

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

Split Decision

Will of the council — Choose target instant or sorcery spell. Starting with you, each player votes for denial or duplication. If denial gets more votes, counter the spell. If duplication gets more votes or the vote is tied, copy the spell. You may choose new targets for the copy.

Curse of Vengeance

Enchant player
Whenever enchanted player casts a spell, put a spite counter on Curse of Vengeance.
When enchanted player loses the game, you gain X life and draw X cards, where X is the number of spite counters on Curse of Vengeance.

Tempt with Reflections

Tempting offer — Choose target creature you control. Create a token that's a copy of that creature. Each opponent may create a token that's a copy of that creature. For each opponent who does, create a token that's a copy of that creature.

Chain of Vapor

Return target nonland permanent to its owner's hand. Then that permanent's controller may sacrifice a land of their choice. If the player does, they may copy this spell and may choose a new target for that copy.

Cabal Coffers

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

Pendant of Prosperity

Pendant of Prosperity enters under the control of an opponent of your choice.
{2}, {T}: Draw a card, then you may put a land card from your hand onto the battlefield. Pendant of Prosperity's owner draws a card, then that player may put a land card from their hand onto the battlefield.

Karn, Scion of Urza

+1: Reveal the top two cards of your library. An opponent chooses one of them. Put that card into your hand and exile the other with a silver counter on it.
−1: Put a card you own with a silver counter on it from exile into your hand.
−2: Create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."

Boneyard Parley

Exile up to five target creature cards from graveyards. An opponent separates those cards into two piles. Put all cards from the pile of your choice onto the battlefield under your control and the rest into their owners' graveyards.

Watery Grave

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

Infernal Offering

Choose an opponent. You and that player each sacrifice a creature. Each player who sacrificed a creature this way draws two cards.
Choose an opponent. Return a creature card from your graveyard to the battlefield, then that player returns a creature card from their graveyard to the battlefield.

Do or Die

Separate all creatures target player controls into two piles. Destroy all creatures in the pile of that player's choice. They can't be regenerated.

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.

Sol Ring

Fortune's Favor

Target opponent looks at the top four cards of your library and separates them into a face-down pile and a face-up pile. Put one pile into your hand and the other into your graveyard.

Minds Aglow

Join forces — Starting with you, each player may pay any amount of mana. Each player draws X cards, where X is the total amount of mana paid this way.

Scheming Symmetry

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

Morphic Pool

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

Atris, Oracle of Half-Truths

Menace
When Atris, Oracle of Half-Truths enters, target opponent looks at the top three cards of your library and separates them into a face-down pile and a face-up pile. Put one pile into your hand and the other into your graveyard.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.