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.

You may pay {1}{B} rather than pay this spell's mana cost.

If the {1}{B} cost was paid, an opponent draws a card.

Exile target creature or planeswalker.

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.

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.

Equipped creature gets +1/+1 for each land you control.

Equip legendary creature {3}

Equip {7}

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Target player draws two cards and loses 2 life.

Bojuka Bog enters the battlefield tapped.

When Bojuka Bog enters the battlefield, exile target player's graveyard.

{T}: Add {B}.

You may look at the top card of your library any time.

You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.

{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

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

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

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

{T}: Add {C}.

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

Castle Locthwain enters the battlefield tapped unless you control a Swamp.

{T}: Add {B}.

{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity.

Equip commander {3}

Equip {5}

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Add {B}{B}{B}.

{B}{B}: Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)

Shadow (This creature can block or be blocked by only creatures with shadow.)

If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.

{T}, Sacrifice Dauthi Voidwalker: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

If you control a commander, you may cast this spell without paying its mana cost.

Exile target creature.

Target creature gets -1/-1 until end of turn for each Swamp you control.

Search your library for a card, put that card into your hand, then shuffle.

Whenever a Swamp enters the battlefield under your control, choose one --

• You draw a card and you lose 1 life.

• Dread Presence deals 2 damage to any target and you gain 2 life.

Enchant creature

Enchanted creature has lifelink and "Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature." (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

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

If it's not your turn, you may exile a black card from your hand rather than pay this spell's mana cost.

Destroy all creatures that entered the battlefield this turn.

Destroy target nonartifact creature.

Whenever a creature you control dies, each other player sacrifices a creature.

When Gray Merchant of Asphodel enters the battlefield, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

{B}, Pay 2 life: Draw a card.

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

Hideaway 4 (When this land enters the battlefield, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)

Howltooth Hollow enters the battlefield tapped.

{T}: Add {B}.

{B}, {T}: You may play the exiled card without paying its mana cost if each player has no cards in hand.

Change the target of target spell with a single target. You lose life equal to that spell's mana value.

{T}: Add {B}.

{1}{B}{B}, {T}, Sacrifice Infernal Idol: You draw two cards and you lose 2 life.

Black spells you cast cost {1} less to cast.

({B/P} can be paid with either {B} or 2 life.)

Lifelink

For each {B} in a cost, you may pay 2 life rather than pay that mana.

Whenever you cast a black spell, put a +1/+1 counter on K'rrik, Son of Yawgmoth.

Korlash, Heir to Blackblade's power and toughness are each equal to the number of Swamps you control.

{1}{B}: Regenerate Korlash.

Grandeur -- Discard another card named Korlash, Heir to Blackblade: Search your library for up to two Swamp cards, put them onto the battlefield tapped, then shuffle.

+1: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.

-3: Target creature gets +X/+X or -X/-X until end of turn, where X is the number of Swamps you control.

-6: You get an emblem with "Swamps you control have '{T}: Add {B}{B}{B}{B}.'"

Lifelink

Whenever another nontoken creature you control dies, exile Liliana, Heretical Healer, then return her to the battlefield transformed under her owner's control. If you do, create a 2/2 black Zombie creature token.

+2: Each player discards a card.

-X: Return target nonlegendary creature card with mana value X from your graveyard to the battlefield.

-8: You get an emblem with "Whenever a creature dies, return it to the battlefield under your control at the beginning of the next end step."

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Flying

Whenever Lord of the Void deals combat damage to a player, exile the top seven cards of that player's library, then put a creature card from among them onto the battlefield under your control.

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

Minas Morgul, Dark Fortress enters the battlefield 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.)

Flash

Indestructible

When Mithril Coat enters the battlefield, attach it to target legendary creature you control.

Equipped creature has indestructible.

Equip {3}

All creatures get -1/-1 until end of turn for each Swamp you control.

Myriad Landscape enters the battlefield tapped.

{T}: Add {C}.

{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Equipped creature has menace, deathtouch, annihilator 1, and "Whenever an opponent sacrifices a nontoken permanent, put that card onto the battlefield under your control unless that player pays 3 life." (Whenever a creature with annihilator 1 attacks, defending player sacrifices a permanent.)

Equip {3}

Skip your draw step.

Whenever you discard a card, exile that card from your graveyard.

Pay 1 life: Exile the top card of your library face down. Put that card into your hand at the beginning of your next end step.

Whenever you tap a Swamp for mana, add an additional {B}.

{B}: Nirkana Revenant gets +1/+1 until end of turn.

Flash

When Orcish Bowmasters enters the battlefield and whenever an opponent draws a card except the first one they draw in each of their draw steps, Orcish Bowmasters deals 1 damage to any target. Then amass Orcs 1.

At the beginning of your upkeep, you draw a card and you lose 1 life.

Flying

Dynastic Advisor -- When Plasmancer enters the battlefield, search your library for a basic Swamp card, reveal it, put it into your hand, then shuffle.

Flying, haste

Whenever Rankle, Master of Pranks deals combat damage to a player, choose any number --

• Each player discards a card.

• Each player loses 1 life and draws a card.

• Each player sacrifices a creature.

Scry 2, then draw two cards. You lose 2 life.

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

{T}: Add {C}.

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

{T}: Add one mana of any color.

{T}: Add three mana of any one color. Activate only if you control three or more lands with the same name.

Enchant creature

Enchanted creature has "{B}: This creature gets +1/+1 until end of turn."

When enchanted creature dies, return that card to the battlefield under your control.

{T}: Add {B}.

{B}, {T}: Target legendary creature gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Target player draws two cards and loses 2 life.

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

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

When Solemn Simulacrum dies, you may draw a card.

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)

Equip {1}

Equipped creature gets +1/+1.

Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Equip {2}

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

As The Black Gate enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.

{T}: Add {B}.

{1}{B}, {T}: Choose a player with the most life or tied for most life. Target creature can't be blocked by creatures that player controls this turn.

{T}: Add {C}.

Whenever a legendary creature enters the battlefield under your control, you may have The Irencrag become a legendary Equipment artifact named Everflame, Heroes' Legacy. If you do, it gains equip {3} and "Equipped creature gets +3/+3" and loses all other abilities.

At the beginning of each end step, if a player discarded a card this turn, create a 1/1 black Bird creature token with flying and "This creature can't block."

{3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.

At the beginning of each end step, if an opponent discarded a card this turn, you draw a card and you lose 1 life.

{4}{B}{B}: Each opponent with no cards in hand loses 10 life.

As an additional cost to cast this spell, pay X life.

All creatures get -X/-X until end of turn.

Equipped creature has nonbasic landwalk. (It can't be blocked as long as defending player controls a nonbasic land.)

Equip {2}

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

Deathtouch

Boast -- {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)

{T}: Add {C}.

{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

Creatures you control have lifelink.

{2}{B}{B}, {T}: Return target creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step. If it would leave the battlefield, exile it instead of putting it anywhere else. Activate only as a sorcery.

Wishclaw Talisman enters the battlefield with three wish counters on it.

{1}, {T}, Remove a wish counter from Wishclaw Talisman: Search your library for a card, put it into your hand, then shuffle. An opponent gains control of Wishclaw Talisman. Activate only during your turn.