Arvinox, the Mind Flail

Arvinox, the Mind Flail isn't a creature unless you control three or more permanents you don't own.
At the beginning of your end step, exile the bottom card of each opponent's library face down. For as long as those cards remain exiled, you may look at them, you may cast permanent spells from among them, and you may spend mana as though it were mana of any color to cast those spells.

Plains

Terramorphic Expanse

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

Talisman of Hierarchy

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

Archery Training

Enchant creature
At the beginning of your upkeep, you may put an arrow counter on Archery Training.
Enchanted creature has "{T}: This creature deals X damage to target attacking or blocking creature, where X is the number of arrow counters on Archery Training."

Murder

Myth Realized

Whenever you cast a noncreature spell, put a lore counter on Myth Realized.
{2}{W}: Put a lore counter on Myth Realized.
{W}: Until end of turn, Myth Realized becomes a Monk Avatar creature in addition to its other types and gains "This creature's power and toughness are each equal to the number of lore counters on it."

Go for the Throat

Starnheim Courser

Flying
Artifact and enchantment spells you cast cost {1} less to cast.

Nowhere to Run

Flash
When Nowhere to Run enters, target creature an opponent controls gets -3/-3 until end of turn.
Creatures your opponents control can be the targets of spells and abilities as though they didn't have hexproof. Ward abilities of those creatures don't trigger.

Sign in Blood

Target player draws two cards and loses 2 life.

Soaring Lightbringer

Flying
Other enchantment creatures you control have flying.
Whenever you attack a player, create a 1/1 white Glimmer enchantment creature token that's tapped and attacking that player.

Reconnaissance

{0}: Remove target attacking creature you control from combat and untap it. (If you activate during end of combat, the creature will untap after it deals combat damage.)

Commander's Sphere

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

Tortured Existence

{B}, Discard a creature card: Return target creature card from your graveyard to your hand.

Swords to Plowshares

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

Aphemia, the Cacophony

Flying
At the beginning of your end step, you may exile an enchantment card from your graveyard. If you do, create a 2/2 black Zombie creature token.

Hopeless Nightmare

When Hopeless Nightmare enters, each opponent discards a card and loses 2 life.
When Hopeless Nightmare is put into a graveyard from the battlefield, scry 2.
{2}{B}: Sacrifice Hopeless Nightmare.

Phyrexian Reclamation

{1}{B}, Pay 2 life: Return target creature card from your graveyard to your hand.

Fear of Surveillance

Vigilance
Whenever Fear of Surveillance attacks, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Mesa Enchantress

Whenever you cast an enchantment spell, you may draw a card.

Pacifism

Enchant creature
Enchanted creature can't attack or block.

Arcane Signet

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

Archetype of Courage

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

Breathe Your Last

Destroy target creature or planeswalker. You gain 1 life for each of its colors.

Swamp

Adanto, the First Fort

(Transforms from Legion's Landing.)
{T}: Add {W}.
{2}{W}, {T}: Create a 1/1 white Vampire creature token with lifelink.

Legion's Landing

When Legion's Landing enters, create a 1/1 white Vampire creature token with lifelink.
When you attack with three or more creatures, transform Legion's Landing.

Legion's Landing // Adanto, the First Fort

Victor, Valgavoth's Seneschal

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, surveil 2 if this is the first time this ability has resolved this turn. If it's the second time, each opponent discards a card. If it's the third time, put a creature card from a graveyard onto the battlefield under your control.

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Doomwake Giant

Constellation — Whenever Doomwake Giant or another enchantment you control enters, creatures your opponents control get -1/-1 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.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Blind Obedience

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Artifacts and creatures your opponents control enter tapped.

Obscura Storefront

When Obscura Storefront enters, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Ultimate Price

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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.)

All That Glitters

Enchant creature
Enchanted creature gets +1/+1 for each artifact and/or enchantment you control.

Hero's Downfall

Archon of Sun's Grace

Flying, lifelink
Pegasus creatures you control have lifelink.
Constellation — Whenever an enchantment you control enters, create a 2/2 white Pegasus creature token with flying.

Bitter Triumph

As an additional cost to cast this spell, discard a card or pay 3 life.
Destroy target creature or planeswalker.

Night's Whisper

Elegant Rotunda

When you unlock this door, put a +1/+1 counter on each of up to two target creatures.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Grand Entryway

When you unlock this door, create a 1/1 white Glimmer enchantment creature token.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Grand Entryway // Elegant Rotunda

Unholy Strength

Enchant creature
Enchanted creature gets +2/+1.

Hateful Eidolon

Lifelink
Whenever an enchanted creature dies, draw a card for each Aura you controlled that was attached to it.

Withering Torment

Destroy target creature or enchantment. You lose 2 life.

Isolated Chapel

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

Gruesome Deformity

Enchant creature
Enchanted creature has intimidate. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Sheltered by Ghosts

Enchant creature you control
When Sheltered by Ghosts enters, exile target nonland permanent an opponent controls until Sheltered by Ghosts leaves the battlefield.
Enchanted creature gets +1/+0 and has lifelink and ward {2}.

Strength of Lunacy

Enchant creature
Enchanted creature gets +2/+1 and has protection from white.
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Hopeful Vigil

When Hopeful Vigil enters, create a 2/2 white Knight creature token with vigilance.
When Hopeful Vigil is put into a graveyard from the battlefield, scry 2.
{2}{W}: Sacrifice Hopeful Vigil.

Underworld Coinsmith

Constellation — Whenever Underworld Coinsmith or another enchantment you control enters, you gain 1 life.
{W}{B}, Pay 1 life: Each opponent loses 1 life.

Doom Blade

Canonized in Blood

At the beginning of your end step, if you descended this turn, put a +1/+1 counter on target creature you control. (You descended if a permanent card was put into your graveyard from anywhere.)
{5}{B}{B}, Sacrifice Canonized in Blood: Create a 4/3 white and black Vampire Demon creature token with flying.

Nyx-Fleece Ram

At the beginning of your upkeep, you gain 1 life.

Spirit Link

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Whenever enchanted creature deals damage, you gain that much life.

Sol Ring

Serra's Blessing

Creatures you control have vigilance. (Attacking doesn't cause them to tap.)

Lurrus of the Dream-Den

Companion — Each permanent card in your starting deck has mana value 2 or less. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Lifelink
Once during each of your turns, you may cast a permanent spell with mana value 2 or less from your graveyard.

Infernal Grasp

Destroy target creature. You lose 2 life.

Orzhov Signet

March from the Black Gate

When March from the Black Gate enters and whenever an Army you control attacks, amass Orcs 1. (Put a +1/+1 counter 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.)

Feast of the Victorious Dead

At the beginning of your end step, if one or more creatures died this turn, you gain that much life and distribute that many +1/+1 counters among creatures you control.

Spirit Mantle

Enchant creature
Enchanted creature gets +1/+1 and has protection from creatures.

Shineshadow Snarl

As Shineshadow Snarl enters, you may reveal a Plains or Swamp card from your hand. If you don't, Shineshadow Snarl enters tapped.
{T}: Add {W} or {B}.

Call of the Ring

At the beginning of your upkeep, the Ring tempts you.
Whenever you choose a creature as your Ring-bearer, you may pay 2 life. If you do, draw a card.

Sinister Strength

Enchant creature
Enchanted creature gets +3/+1 and is black.

Spirited Companion

When Spirited Companion enters, draw a card.

Evolving Wilds

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

Command Tower

Grim Guardian

Constellation — Whenever Grim Guardian or another enchantment you control enters, each opponent loses 1 life.

Fear of Lost Teeth

When Fear of Lost Teeth dies, it deals 1 damage to any target and you gain 1 life.

Brave the Sands

Creatures you control have vigilance.
Each creature you control can block an additional creature each combat.