Ring of Valkas

Equipped creature has haste. (It can attack and {T} no matter when it came under your control.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's red.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Have

Thriving Bluff

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

Codex Shredder

{T}: Target player mills a card. (They put the top card of their library into their graveyard.)
{5}, {T}, Sacrifice this artifact: Return target card from your graveyard to your hand.

Mask of the Schemer

Whenever equipped creature deals combat damage to a player, it connives X, where X is the amount of damage it dealt to that player. (Draw X cards, then discard X cards. Put a +1/+1 counter on that creature for each nonland card discarded this way.)
Equip {2}

Compelling Argument

Target player mills five cards.
Cycling {U} ({U}, Discard this card: Draw a card.)

Lonely Arroyo

This land enters tapped.
When this land enters, it deals 1 damage to target opponent.
{T}: Add {W} or {U}.

Perilous Landscape

{T}: Add {C}.
{T}, Sacrifice this land: Search your library for a basic Island, Mountain, or Plains card, put it onto the battlefield tapped, then shuffle.
Cycling {U}{R}{W} ({U}{R}{W}, Discard this card: Draw a card.)

Kykar, Wind's Fury

Flying
Whenever you cast a noncreature spell, create a 1/1 white Spirit creature token with flying.
Sacrifice a Spirit: Add {R}.

Mountain

Crosstown Courier

Whenever this creature deals combat damage to a player, that player mills that many cards.

Divine Resilience

Kicker {2}{W} (You may pay an additional {2}{W} as you cast this spell.)
Target creature you control gains indestructible until end of turn. If this spell was kicked, instead any number of target creatures you control gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Azorius Signet

Archive Trap

If an opponent searched their library this turn, you may pay {0} rather than pay this spell's mana cost.
Target opponent mills thirteen cards.

Nahiri's Machinations

At the beginning of combat on your turn, target creature you control gains indestructible until end of turn.
{1}{R}: This enchantment deals 1 damage to target blocking creature.

Command Tower

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

Evolving Wilds

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

Prairie Stream

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

Fight as One

Choose one or both —
• Target Human creature you control gets +1/+1 and gains indestructible until end of turn.
• Target non-Human creature you control gets +1/+1 and gains indestructible until end of turn.

Proxy

Narset, Enlightened Master

First strike, hexproof
Whenever Narset attacks, exile the top four cards of your library. Until end of turn, you may cast noncreature spells from among those cards without paying their mana costs.

Compulsion

{1}{U}, Discard a card: Draw a card.
{1}{U}, Sacrifice this enchantment: Draw a card.

Imperious Mindbreaker

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Imperious Mindbreaker is paired with another creature, each of those creatures has "Whenever this creature attacks, each opponent mills cards equal to its toughness."

Path of Ancestry

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Stormcatch Mentor

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Instant and sorcery spells you cast cost {1} less to cast.

Laelia, the Blade Reforged

Haste
Whenever Laelia attacks, exile the top card of your library. You may play that card this turn.
Whenever one or more cards are put into exile from your library and/or your graveyard, put a +1/+1 counter on Laelia.

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.)

Memory Erosion

Whenever an opponent casts a spell, that player mills two cards.

Rogue's Passage

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

Whirlwind of Thought

Whenever you cast a noncreature spell, draw a card.

Mindsplice Apparatus

Flash
At the beginning of your upkeep, put an oil counter on this artifact.
Instant and sorcery spells you cast cost {1} less to cast for each oil counter on this artifact.

Court of Cunning

When this enchantment enters, you become the monarch.
At the beginning of your upkeep, any number of target players each mill two cards. If you're the monarch, each of those players mills ten cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Teach by Example

({U/R} can be paid with either {U} or {R}.)
When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Thousand-Year Storm

Whenever you cast an instant or sorcery spell, copy it for each other instant and sorcery spell you've cast before it this turn. You may choose new targets for the copies.

Gold-Forged Thopteryx

Flying, lifelink
Each legendary permanent you control has ward {2}. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Glyph Elemental

Bestow {1}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Landfall — Whenever a land you control enters, put a +1/+1 counter on this permanent.
Enchanted creature gets +1/+1 for each +1/+1 counter on this Aura.

Mystic Redaction

At the beginning of your upkeep, scry 1.
Whenever you discard a card, each opponent mills two cards. (They put the top two cards of their library into their graveyard.)

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.

Narset, Enlightened Exile

Creatures you control have prowess.
Whenever Narset attacks, exile target noncreature, nonland card with mana value less than Narset's power from a graveyard and copy it. You may cast the copy without paying its mana cost.

Deranged Assistant

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Mind Sculpt

Adamant Will

Target creature gets +2/+2 and gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Melek, Izzet Paragon

Play with the top card of your library revealed.
You may cast instant and sorcery spells from the top of your library.
Whenever you cast an instant or sorcery spell from your library, copy it. You may choose new targets for the copy.

Thirst for Discovery

Draw three cards. Then discard two cards unless you discard a basic land card.

Island

Tolarian Terror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Goldvein Pick

Equipped creature gets +1/+1.
Whenever equipped creature deals combat damage to a player, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Swiftwater Cliffs

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

Alchemist's Gambit

Cleave {4}{U}{U}{R} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Take an extra turn after this one. During that turn, damage can't be prevented. [At the beginning of that turn's end step, you lose the game.]
Exile Alchemist's Gambit.

Port Town

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

Jeskai Ascendancy

Whenever you cast a noncreature spell, creatures you control get +1/+1 until end of turn. Untap those creatures.
Whenever you cast a noncreature spell, you may draw a card. If you do, discard a card.

Drowned Secrets

Whenever you cast a blue spell, target player mills two cards.

Mystic Monastery

This land enters tapped.
{T}: Add {U}, {R}, or {W}.

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Aegis of the Legion

Equipped creature gets +1/+1 and has mentor. (Whenever it attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever equipped creature mentors a creature, put a shield counter on that creature. (If that creature would be dealt damage or destroyed, remove a shield counter from it instead.)
Equip {3}

Monastery Mentor

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a noncreature spell, create a 1/1 white Monk creature token with prowess.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Keening Stone

{5}, {T}: Target player mills X cards, where X is the number of cards in that player's graveyard.

Sol Ring

Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Manic Scribe

When this creature enters, each opponent mills three cards.
Delirium — At the beginning of each opponent's upkeep, if there are four or more card types among cards in your graveyard, that player mills three cards.

Return the Favor

Spree (Choose one or more additional costs.)
+ {1} — Copy target instant spell, sorcery spell, activated ability, or triggered ability. You may choose new targets for the copy.
+ {1} — Change the target of target spell or ability with a single target.

Winds of Rebuke

Return target nonland permanent to its owner's hand. Each player mills two cards.

Izzet Signet

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Venture Deeper

Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)

Merfolk Secretkeeper

Merfolk Secretkeeper // Venture Deeper

Plains

Fractured Sanity

Each opponent mills fourteen cards.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle this card, each opponent mills four cards.

Slagstorm

Choose one —
• Slagstorm deals 3 damage to each creature.
• Slagstorm deals 3 damage to each player.

Folio of Fancies

Players have no maximum hand size.
{X}{X}, {T}: Each player draws X cards.
{2}{U}, {T}: Each opponent mills cards equal to the number of cards in their hand.

Combustible Gearhulk

First strike
When this creature enters, target opponent may have you draw three cards. If the player doesn't, you mill three cards, then this creature deals damage to that player equal to the total mana value of those cards.

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Bond of Insight

Each player mills four cards. Return up to two instant and/or sorcery cards from your graveyard to your hand. Exile Bond of Insight.

Storm-Kiln Artist

This creature gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Narset of the Ancient Way

+1: You gain 2 life. Add {U}, {R}, or {W}. Spend this mana only to cast a noncreature spell.
−2: Draw a card, then you may discard a card. When you discard a nonland card this way, Narset deals damage equal to that card's mana value to target creature or planeswalker.
−6: You get an emblem with "Whenever you cast a noncreature spell, this emblem deals 2 damage to any target."

Chill of Foreboding

Each player mills five cards.
Flashback {7}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)