It'll Quench Ya!

Counter target spell unless its controller pays {2}.

Circle of Power

You draw two cards and you lose 2 life. Create a 0/1 black Wizard creature token with "Whenever you cast a noncreature spell, this token deals 1 damage to each opponent."
Wizards you control get +1/+0 and gain lifelink until end of turn.

Thriving Isle

This land enters tapped. As it enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Vivi Ornitier

{0}: Add X mana in any combination of {U} and/or {R}, where X is Vivi Ornitier's power. Activate only during your turn and only once each turn.
Whenever you cast a noncreature spell, put a +1/+1 counter on Vivi Ornitier and it deals 1 damage to each opponent.

Headliner Scarlett

Haste
When Headliner Scarlett enters, creatures target player controls can't block this turn.
At the beginning of your upkeep, exile the top card of your library face down. You may look at and play that card this turn.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Fiery Inscription

When this enchantment enters, the Ring tempts you.
Whenever you cast an instant or sorcery spell, this enchantment deals 2 damage to each opponent.

Locke, Treasure Hunter

Locke can't be blocked by creatures with greater power.
Mug — Whenever Locke attacks, each player mills a card. If a land card was milled this way, create a Treasure token. Until end of turn, you may cast a spell from among those cards.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Spirebluff Canal

This land enters tapped unless you control two or fewer other lands.
{T}: Add {U} or {R}.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Thriving Moor

This land enters tapped. As it enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Smoldering Marsh

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

Claim the Precious

Destroy target creature. The Ring tempts you.

Swamp

Ensnared by the Mara

Each opponent faces a villainous choice — They exile cards from the top of their library until they exile a nonland card, then you may cast that card without paying its mana cost, or that player exiles the top four cards of their library and Ensnared by the Mara deals damage equal to the total mana value of those exiled cards to that player.

Mountain

Gollum's Bite

Target creature gets -2/-2 until end of turn.
{3}{B}, Exile this card from your graveyard: The Ring tempts you. Activate only as a sorcery.

Cyber Conversion

Turn target creature face down. It's a 2/2 Cyberman artifact creature.

Damnation

Destroy all creatures. They can't be regenerated.

Minamo, School at Water's Edge

{T}: Add {U}.
{U}, {T}: Untap target legendary permanent.

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}.

Queen Brahne

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever Queen Brahne attacks, create a 0/1 black Wizard creature token with "Whenever you cast a noncreature spell, this token deals 1 damage to each opponent."

Abaddon the Despoiler

Trample
Mark of Chaos Ascendant — During your turn, spells you cast from your hand with mana value X or less have cascade, where X is the total amount of life your opponents have lost this turn.

Garland, Royal Kidnapper

When Garland enters, target opponent becomes the monarch.
Whenever an opponent becomes the monarch, gain control of target creature that player controls for as long as they're the monarch.
Creatures you control but don't own get +2/+2 and can't be sacrificed.

Sticky Fingers

Enchant creature
Enchanted creature has menace and "Whenever this creature deals combat damage to a player, create a Treasure token." (It can't be blocked except by two or more creatures. The token is an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
When enchanted creature dies, draw a card.

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.

Island

Frostboil Snarl

As this land enters, you may reveal an Island or Mountain card from your hand. If you don't, this land enters tapped.
{T}: Add {U} or {R}.

Haunted Ridge

This land enters tapped unless you control two or more other lands.
{T}: Add {B} or {R}.

Terminate

Destroy target creature. It can't be regenerated.

Propaganda

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

Scheming Symmetry

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

Saruman, the White Hand

Whenever you cast a noncreature spell, amass Orcs X, where X is that spell's mana value. (Put X +1/+1 counters on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.)
Goblins and Orcs you control have ward {2}.

Bribery

Search target opponent's library for a creature card and put that card onto the battlefield under your control. Then that player shuffles.

Self-Destruct

Target creature you control deals X damage to any other target and X damage to itself, where X is its power.

Snort

Each player may discard their hand and draw five cards. Then Snort deals 5 damage to each opponent who discarded their hand this way.
Flashback {5}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Unexpected Windfall

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Lord of the Nazgûl

Flying
Wraiths you control have protection from Ring-bearers.
Whenever you cast an instant or sorcery spell, create a 3/3 black Wraith creature token with menace. Then if you control nine or more Wraiths, Wraiths you control have base power and toughness 9/9 until end of turn.

Big Score

Torrential Gearhulk

Flash
When this creature enters, you may cast target instant card from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Black Waltz No. 3

Flying, deathtouch
Whenever you cast a noncreature spell, Black Waltz No. 3 deals 2 damage to each opponent.

Serum Visions

Risky Research

Surveil 2, then draw two cards. You lose 2 life. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Minas Morgul, Dark Fortress

Minas Morgul enters tapped.
{T}: Add {B}.
{3}{B}, {T}: Put a shadow counter on target creature. For as long as that creature has a shadow counter on it, it's a Wraith in addition to its other types. (A creature with shadow can block or be blocked by only creatures with shadow.)