Commander creatures you own have "Whenever this creature becomes tapped, it and other creatures you control that share a creature type with it each get +2/+0 and gain undying until end of turn." (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

As Door of Destinies enters the battlefield, choose a creature type. Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies. Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

As an additional cost to cast this spell, sacrifice a creature. Search your library for a card, put that card into your hand, then shuffle.

Choose a creature type. Draw a card for each permanent you control of that type.

Enchant creature you control At the beginning of your upkeep, create a token that's a copy of enchanted creature, except the token is 1/1. When enchanted creature dies, if that creature was a Horror, return Endless Evil to its owner's hand.

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.

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.)

Equipped creature gets +1/-1. Whenever equipped creature dies, draw two cards. Equip {1}

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.

Changeling (This card is every creature type.) As Bloodline Pretender enters the battlefield, choose a creature type. Whenever another creature of the chosen type enters the battlefield under your control, put a +1/+1 counter on Bloodline Pretender.

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.

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.

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.

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.

Flying Whenever you draw your second card each turn, put a +1/+1 counter on Gurgling Anointer. When Gurgling Anointer dies, return another target creature card with mana value less than or equal to Gurgling Anointer's power from your graveyard to the battlefield.

Trample When Hunted Horror enters the battlefield, target opponent creates two 3/3 green Centaur creature tokens with protection from black.

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.

Bestow {2}{B}{B} (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 to a creature.) Nighthowler and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.

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.

When Ravenous Chupacabra enters the battlefield, destroy target creature an opponent controls.

As Sewer Nemesis enters the battlefield, choose a player. Sewer Nemesis's power and toughness are each equal to the number of cards in the chosen player's graveyard. Whenever the chosen player casts a spell, that player mills a card.

Flash At the beginning of your upkeep, each player mills three cards. You may exile a creature card from among the cards milled this way. If you do, Shadow Kin becomes a copy of that card, except it has this ability.

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.

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Bojuka Bog enters the battlefield tapped. When Bojuka Bog enters the battlefield, exile target player's graveyard. {T}: Add {B}.

As Choked Estuary enters the battlefield, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters the battlefield tapped. {T}: Add {U} or {B}.

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

{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}.

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp. {T}: Add {U} or {B}.

({T}: Add {U}.)

Morphic Pool enters the battlefield tapped unless you have two or more opponents. {T}: Add {U} or {B}.

{T}: Add {C}. {1}{U}{B}, {T}: Target player mills three 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.)

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

({T}: Add {U} or {B}.) Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

({T}: Add {B}.)

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

{T}: Add {B}. Channel — {3}{B}, Discard Takenuma, Abandoned Mire: Mill three cards, then return a creature or planeswalker card from your graveyard to your hand. This ability costs {1} less to activate for each legendary creature you control.

Waterfront District enters the battlefield tapped. {T}: Add {U} or {B}. {2}{U}{B}, {T}, Sacrifice Waterfront District: Draw a card.

When Court of Cunning enters the battlefield, 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.)

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

Whenever a permanent becomes untapped, that permanent's controller mills a card.

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

Whenever you draw a card, each opponent mills two cards.

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep. You draw a card at the beginning of the next turn's upkeep.

Counter target spell.

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

{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.

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

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.

{T}: Add one mana of any color. {1}, {T}: Untap target legendary creature you control.

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

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

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

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.

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.

Choose one — • Counter target spell with mana value less than or equal to the number of cards in its controller's graveyard. • Destroy target creature with mana value less than or equal to the number of cards in its controller's graveyard.

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

Destroy target creature or planeswalker.

Choose a creature type. Destroy all creatures that aren't of the chosen type.

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Choose a creature type. Return all creatures that aren't of the chosen type to their owners' hands.

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

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

Enchant creature card in a graveyard When Animate Dead enters the battlefield, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it. Enchanted creature gets -1/-0.

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on Bloodchief Ascension. (Damage causes loss of life.) Whenever a card is put into an opponent's graveyard from anywhere, if Bloodchief Ascension has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.