Each player sacrifices all permanents they control that are one or more colors.

Whenever another permanent enters the battlefield under your control, each opponent mills a card.

{3}: Target player mills three cards.

Changeling (This card is every creature type.)

{T}: Target creature gains all creature types until end of turn.

{T}: Target creature loses all creature types until end of turn.

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

Change the text of target spell or permanent by replacing all instances of one creature type with another. The new creature type can't be Wall. (This effect lasts indefinitely.)

{T}: Add {C}.

Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Target player reveals the top four cards of their library. You choose two of those cards and put them into that player's graveyard. Put the rest on top of their library in any order.

When Biblioplex Kraken enters the battlefield, scry 3. (Look at the top three cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Whenever Biblioplex Kraken attacks, you may return another creature you control to its owner's hand. If you do, Biblioplex Kraken can't be blocked this turn.

You may have Body Double enter as a copy of any creature card in a graveyard.

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.

Horrors you control have menace.

Whenever a Horror you control deals combat damage to a player, that player mills that many cards.

At the beginning of your end step, choose target artifact or creature card in an opponent's graveyard that was put there from their library this turn. Put it onto the battlefield under your 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.

Whenever Cephalid Constable deals combat damage to a player, return up to that many target permanents that player controls to their owner's hand.

{T}: Target player draws a card, then discards a card.

At the beginning of your upkeep, put a shred counter on Cephalid Vandal. Then mill a card for each shred counter on Cephalid Vandal.

Charcoal Diamond enters tapped.

{T}: Add {B}.

Whenever you draw a card, put a +1/+1 counter on Chasm Skulker.

When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)

Return target permanent to its owner's hand. Its controller loses 3 life.

Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

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

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.

Cruel Somnophage's power and toughness are each equal to the number of creature cards in all graveyards.

---

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

{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}.

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

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

{3}, {T}, Sacrifice Dreamstone Hedron: Draw three cards.

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.

{T}: Add {U} or {B}.

{T}: Add {C}.

{3}: Return Drownyard Temple from your graveyard to the battlefield tapped.

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.

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

Return all noncreature, nonland permanents to their owners' hands.

Put target creature card from a graveyard onto the battlefield under your control with a corpse counter on it. If that creature would leave the battlefield, exile it instead of putting it anywhere else.

You take the initiative.

Escape--{3}{B}{B}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

{T}: Add {C}.

{2}, {T}: Each player draws a card, then discards a card.

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Whenever Guiltfeeder attacks and isn't blocked, defending player loses 1 life for each card in their graveyard.

You may cast Harbinger of the Tides as though it had flash if you pay {2} more to cast it. (You may cast it any time you could cast an instant.)

When Harbinger of the Tides enters the battlefield, you may return target tapped creature an opponent controls to its owner's hand.

Enchant creature, land, or planeswalker

Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Destroy target creature. You lose 2 life.

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)

When Invasion of Amonkhet enters the battlefield, each player mills three cards, then each opponent discards a card and you draw a card. (To mill three cards, a player puts the top three cards of their library into their graveyard.)

You may have Lazotep Convert enter the battlefield as a copy of any creature card in a graveyard, except it's a 4/4 black Zombie in addition to its other colors and types.

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

As Kindred Discovery enters the battlefield, choose a creature type.

Whenever a creature you control of the chosen type enters the battlefield or attacks, draw a card.

{2}{U}: Goad target creature. Whenever that creature attacks one of your opponents this turn, you draw a card. (A goaded creature attacks each combat if able and attacks a player other than you if able, until your next turn.)

Choose target creature. You lose 2 life. Until end of turn, that creature gains "When this creature dies, return it to the battlefield tapped under its owner's control."

Malakir Mire enters the battlefield tapped.

{T}: Add {B}.

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

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

{T}: Add {C}.

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

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

When Monstrosity of the Lake enters the battlefield, you may pay {5}. If you do, tap all creatures your opponents control, then put a stun counter on each of those creatures. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Islandcycling {2} ({2}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Flying

When Nautiloid Ship enters the battlefield, exile target player's graveyard.

Whenever Nautiloid Ship deals combat damage to a player, you may put a creature card exiled with Nautiloid Ship onto the battlefield under your control.

Crew 3

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

{T}: Add {C}.

{1}{U}{B}, {T}: Target player mills three cards.

Nevinyrral's Disk enters the battlefield tapped.

{1}, {T}: Destroy all artifacts, creatures, and enchantments.

You draw two cards and you lose 2 life.

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, 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.

{2}, {T}: Target opponent exiles the top card of their library. You may play that card this turn.

Enchant creature

Enchanted creature doesn't untap during its controller's untap step.

At the beginning of your upkeep, target opponent mills three cards, then you draw a card for each land card put into their graveyard this way.

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

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

{3}{B}: Target opponent reveals a card at random from their hand. Target creature gets -X/-X until end of turn, where X is the revealed card's mana value. Activate only as a sorcery.

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.

Counter target spell. Its controller mills two cards.

{2}, {T}: Target opponent mills three cards. Put a land card from their graveyard onto the battlefield tapped under your control. It gains "If this land would leave the battlefield, exile it instead of putting it anywhere else."

{10}, {T}, Sacrifice Realmbreaker, the Invasion Tree: Search your library for any number of Praetor cards, put them onto the battlefield, then shuffle.

{T}: Add one mana of any type that a land you control could produce.

As Reflections of Littjara enters the battlefield, choose a creature type.

Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

You have no maximum hand size.

{T}: Add {C}.

Restless Reef enters the battlefield tapped.

{T}: Add {U} or {B}.

{2}{U}{B}: Until end of turn, Restless Reef becomes a 4/4 blue and black Shark creature with deathtouch. It's still a land.

Whenever Restless Reef attacks, target player mills four cards.

{T}: Add {C}.

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

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

You may choose not to untap Sand Squid during your untap step.

{T}: Tap target creature. That creature doesn't untap during its controller's untap step for as long as Sand Squid remains tapped.

Shipwreck Marsh enters the battlefield tapped unless you control two or more other lands.

{T}: Add {U} or {B}.

Each player may put an artifact, creature, enchantment, or land card from their hand onto the battlefield.

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

When Shriekmaw enters the battlefield, destroy target nonartifact, nonblack creature.

Evoke {1}{B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Sky Diamond enters the battlefield tapped.

{T}: Add {U}.

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.

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

{T}: Add {C}.

{U/B}, {T}: Add {U}{U}, {U}{B}, or {B}{B}.

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

{T}: Add {C}.

{T}: Add {U} or {B}. Activate only if you control a Swamp.

{T}: Add {C}.

{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

{T}: Add {C}{C}. Activate only if you control five or more lands.

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

Indestructible

As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

At the beginning of your upkeep, scry 1.

{1}{U}: Target creature you control can't be blocked this turn.

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.

Defender

Thing in the Ice enters the battlefield with four ice counters on it.

Whenever you cast an instant or sorcery spell, remove an ice counter from Thing in the Ice. Then if it has no ice counters on it, transform it.

When this creature transforms into Awoken Horror, return all non-Horror creatures to their owners' hands.

{1}: Choose a creature type other than Wall. Target creature becomes that type until end of turn.

As Urza's Incubator enters the battlefield, choose a creature type.

Creature spells of the chosen type cost {2} less to cast.

Skulk (This creature can't be blocked by creatures with greater power.)

Whenever Wharf Infiltrator deals combat damage to a player, you may draw a card. If you do, discard a card.

Whenever you discard a creature card, you may pay {2}. If you do, create a 3/2 colorless Eldrazi Horror creature token.

Any number of target opponents each discard their hands, then draw seven cards.

Draw a card.

Islandwalk, swampwalk (This creature can't be blocked as long as defending player controls an Island or a Swamp.)

Whenever Wrexial, the Risen Deep deals combat damage to a player, you may cast target instant or sorcery card from that player's graveyard without paying its mana cost. If that spell would be put into a graveyard, exile it instead.

Hive Mind -- Whenever a player mills one or more creature cards, you create a 1/1 black Horror creature token.

{1}, {T}: Target player mills three cards.

Choose a Background (You can have a Background as a second commander.)