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

{T}: Add {U} or {B}. {U}{B}: Dimir Keyrune becomes a 2/2 blue and black Horror artifact creature until end of turn and can't be blocked this turn.

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

As Herald's Horn enters the battlefield, choose a creature type. Creature spells you cast of the chosen type cost {1} less to cast. At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.) Equip {0}

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

{T}: Add {C}{C}.

{T}: Add one mana of any color. {1}, {T}: Untap another target artifact. {2}, {T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.) {3}, {T}: Target creature can't be blocked this turn.

As Urza's Incubator enters the battlefield, choose a creature type. Creature spells of the chosen type cost {2} less to cast.

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Flash Ward {2} Probing Telepathy — Whenever a creature entering the battlefield under an opponent's control causes a triggered ability of that creature to trigger, you may copy that ability. You may choose new targets for the copy.

Whenever an enchantment you control is put into a graveyard from the battlefield, draw a card.

Flying, deathtouch When Baleful Strix enters the battlefield, draw a card.

Flying At the beginning of your end step, exile the top card of each opponent's library. You may play those cards for as long as they remain exiled. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it. Whenever a nonland permanent an opponent owns enters the battlefield under your control, they lose life equal to its mana value.

All Nightmares get +1/+1. {B}{B}{B}, Pay 3 life: Put target creature card from a graveyard onto the battlefield under your control. That creature is black and is a Nightmare in addition to its other creature types. When Chainer, Dementia Master leaves the battlefield, exile all Nightmares.

Consuming Aberration's power and toughness are each equal to the number of cards in your opponents' graveyards. Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Flying When Dark Hatchling enters the battlefield, destroy target nonblack creature. It can't be regenerated.

Shadow (This creature can block or be blocked by only creatures with shadow.) Dauthi Horror can't be blocked by white creatures.

As an additional cost to cast this spell, sacrifice a creature, discard a card, or pay 4 life. When Dusk Mangler enters the battlefield, each opponent sacrifices a creature, discards a card, and loses 4 life.

Menace Whenever Elder Brain attacks a player, exile all cards from that player's hand, then they draw that many cards. You may play lands and cast spells from among the exiled cards for as long as they remain exiled. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it.

Whenever a creature you control becomes blocked, you may return it to its owner's hand. Whenever one or more creatures you control deal combat damage to a player, draw a card.

Aberrant Tinkering — When Grell Philosopher enters the battlefield and at the beginning of your upkeep, each Horror you control gains all activated abilities of target artifact an opponent controls until end of turn. You may spend blue mana as though it were mana of any color to activate those abilities.

Flash This spell can't be countered. Whenever you cast a spell, choose up to one — • Return target spell you don't control to its owner's hand. • Return target nonland permanent to its owner's hand.

Dominate Monster — When Mind Flayer enters the battlefield, gain control of target creature for as long as you control Mind Flayer.

Whenever Nemesis of Reason attacks, defending player mills ten cards.

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.) Suspend 7—{1}{B} (Rather than cast this card from your hand, you may pay {1}{B} and exile it with seven time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.) Whenever a card is put into an opponent's graveyard from anywhere, if Nihilith is suspended, you may remove a time counter from Nihilith.

Flash Flying Exploit (When this creature enters the battlefield, you may sacrifice a creature.) When Overcharged Amalgam exploits a creature, counter target spell, activated ability, or triggered ability.

{1}{B}: Return Reassembling Skeleton from your graveyard to the battlefield tapped.

Whenever Sludge Monster enters the battlefield or attacks, put a slime counter on up to one other target creature. Non-Horror creatures with slime counters on them lose all abilities and have base power and toughness 2/2.

Uchuulon's power is equal to the number of Crabs, Oozes, and/or Horrors you control. Horrific Symbiosis — At the beginning of your end step, exile up to one target creature card from an opponent's graveyard. If you do, create a token that's a copy of Uchuulon.

Indestructible Shadow (This creature can block or be blocked by only creatures with shadow.) Morbid — At the beginning of each end step, if a creature died this turn, put a +1/+1 counter on Vashta Nerada.

When Woe Strider enters the battlefield, create a 0/1 white Goat creature token. Sacrifice another creature: Scry 1. Escape—{3}{B}{B}, Exile four other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.) Woe Strider escapes with two +1/+1 counters on it.

Enchant noncommander creature You control enchanted creature. Enchanted creature gets +2/+2 and can't be blocked unless it's attacking its owner or a permanent its owner controls.

Whenever a creature dies, put a charge counter on Black Market. At the beginning of your precombat main phase, add {B} for each charge counter on Black Market.

Whenever a blue creature enters the battlefield under your control, you may have target player draw a card. Whenever a black creature enters the battlefield under your control, you may have target player discard a card.

Flash Enchant creature Enchanted creature loses all abilities and is a black Skeleton creature with base power and toughness 1/1. (It loses all other card types and creature types.)

When Hopeless Nightmare enters the battlefield, 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.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I — Each player mills four cards. Then you may exile a creature or planeswalker card from each graveyard. II, III — Until end of turn, you may cast spells from among cards exiled with King Narfi's Betrayal, and you may spend mana as though it were mana of any color to cast those spells.

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield. You may cast spells as though they had flash.

You may cast spells from your hand without paying their mana costs.

Counter target spell.

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

You may cast target instant or sorcery card from an opponent's graveyard without paying its mana cost.

Draw X cards, then discard a card.

Choose one — • Counter all other spells. • Switch each creature's power and toughness until end of turn. • Creatures can't be blocked this turn.

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

Creeping Tar Pit enters the battlefield tapped. {T}: Add {U} or {B}. {1}{U}{B}: Creeping Tar Pit becomes a 3/2 blue and black Elemental creature until end of turn and can't be blocked this turn. It's still a land.

{1}, {T}: Add {U}{B}.

Dimir Aqueduct enters the battlefield tapped. When Dimir Aqueduct enters the battlefield, return a land you control to its owner's hand. {T}: Add {U}{B}.

Dimir Guildgate enters the battlefield tapped. {T}: Add {U} or {B}.

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

Hidden Cataract enters the battlefield tapped. {T}: Add {U}. {4}{U}, {T}, Sacrifice Hidden Cataract: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Hidden Necropolis enters the battlefield tapped. {T}: Add {B}. {4}{B}, {T}, Sacrifice Hidden Necropolis: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

({T}: Add {U}.)

Memorial to Genius enters the battlefield tapped. {T}: Add {U}. {4}{U}, {T}, Sacrifice Memorial to Genius: Draw two cards.

Path of Ancestry enters the battlefield 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.)

You have no maximum hand size. {T}: Add {C}.

Shipwreck Marsh enters the battlefield tapped unless you control two or more other lands. {T}: Add {U} or {B}.

({T}: Add {B}.)

Temple of Deceit enters the battlefield tapped. When Temple of Deceit enters the battlefield, scry 1. {T}: Add {U} or {B}.

Draw three cards, then discard a card.

Roll two d8 and choose one result. Draw cards equal to that result. Then you may cast an instant or sorcery spell with mana value less than or equal to the other result from your hand without paying its mana cost.

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.) Search your library for a card, exile it face down, then shuffle. If this spell was bargained, you may cast the exiled card without paying its mana cost if that spell's mana value is 4 or less. Put the exiled card into your hand if it wasn't cast this way.

Return target creature card from your graveyard to the battlefield. Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Target opponent chooses X cards from their hand. Look at those cards. You may cast a spell from among them without paying its mana cost.

Each player mills two cards. Then you put a creature card from a graveyard onto the battlefield under your control.

Choose up to four target creatures you don't control. For each of them, that creature's controller faces a villainous choice — That creature becomes a 1/1 white Human creature and loses all abilities, or you create a token that's a copy of it.

Destroy all creatures you don't control and all planeswalkers you don't control.

Look at the top three cards of your library, then put them back in any order. You may shuffle. Draw a card.

Replicate—Tap an untapped Horror you control. (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.) Exile target instant or sorcery card from a graveyard and copy it. You may cast the copy without paying its mana cost. Exile Psionic Ritual.

When Abyssal Gorestalker enters the battlefield, each player sacrifices two creatures.

{1}, {T}: Add {U}{B}.

Equipped creature has reach, "{2}, {T}: Tap target artifact or creature," and "{8}, {T}: Discover 10." (Exile cards from the top of your library until you exile a nonland card with mana value 10 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.) Equip {1}

Descend 8 — The Ancient One can't attack or block unless there are eight or more permanent cards in your graveyard. {2}{U}{B}: Draw a card, then discard a card. When you discard a card this way, target player mills cards equal to its mana value.

Vigilance, menace Descend 8 — {4}{U}{B}: Return Uchbenbak, the Great Mistake from your graveyard to the battlefield with a finality counter on it. Activate only if there are eight or more permanent cards in your graveyard and only as a sorcery. (If a creature with a finality counter on it would die, exile it instead.)

You may mill two cards. Then return up to two creature cards from your graveyard to your hand. (To mill two cards, put the top two cards of your library into your graveyard.)

Choose one — • Target opponent discards two cards. • Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.

(You may cast a legendary instant only if you control a legendary creature or planeswalker.) Destroy target creature. If its controller has more than four cards in hand, they exile cards from their hand equal to the difference.

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

+1: Each player discards a card. −2: Target player sacrifices a creature. −6: Separate all permanents target player controls into two piles. That player sacrifices all permanents in the pile of their choice.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I — The Ring tempts you, then each player mills cards equal to your Ring-bearer's power. II — Destroy all nonlegendary creatures. III — Each opponent loses 1 life for each creature card in that player's graveyard.

When Plaguecrafter enters the battlefield, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

When Skemfar Shadowsage enters the battlefield, choose one — • Each opponent loses X life, where X is the greatest number of creatures you control that have a creature type in common. • You gain X life, where X is the greatest number of creatures you control that have a creature type in common.

Each other player discards a card. You draw a card for each card discarded this way.