Door of Destinies

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.

Heart Sliver

Fungus Sliver

All Sliver creatures have "Whenever this creature is dealt damage, put a +1/+1 counter on it." (It must survive the damage to get the counter.)

Sliver Legion

All Sliver creatures get +1/+1 for each other Sliver on the battlefield.

Sliver Hivelord

Sliver creatures you control have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Brood Sliver

Whenever a Sliver deals combat damage to a player, its controller may create a 1/1 colorless Sliver creature token.

Horned Sliver

Tragic Arrogance

For each player, you choose from among the permanents that player controls an artifact, a creature, an enchantment, and a planeswalker. Then each player sacrifices all other nonland permanents they control.

Swamp

Toxin Sliver

Whenever a Sliver deals combat damage to a creature, destroy that creature. It can't be regenerated.

Forest

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

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.

Constricting Sliver

Sliver creatures you control have "When this creature enters the battlefield, you may exile target creature an opponent controls until this creature leaves the battlefield."

Ashnod's Altar

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Eladamri's Call

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

Plains

Sylvan Library

At the beginning of your draw step, you may draw two additional cards. If you do, choose two cards in your hand drawn this turn. For each of those cards, pay 4 life or put the card on top of your library.

Sidewinder Sliver

All Sliver creatures have flanking. (Whenever a creature without flanking blocks a Sliver, the blocking creature gets -1/-1 until end of turn.)

Mountain

Island

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Plated Sliver

Brushland

{T}: Add {C}.
{T}: Add {G} or {W}. Brushland deals 1 damage to you.

Canopy Vista

({T}: Add {G} or {W}.)
Canopy Vista enters the battlefield tapped unless you control two or more basic lands.

Arcane Signet

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

Telekinetic Sliver

All Slivers have "{T}: Tap target permanent."

Shifting Sliver

Slivers can't be blocked except by Slivers.

Gemhide Sliver

All Slivers have "{T}: Add one mana of any color."

Counterspell

Sliver Hive

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Sliver spell.
{5}, {T}: Create a 1/1 colorless Sliver creature token. Activate only if you control a Sliver.

Sol Ring

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Quick Sliver

Flash
Any player may cast Sliver spells as though they had flash.

Spinneret Sliver

Reflections of Littjara

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.)

Sentinel Sliver

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

Manaweft Sliver

Sliver creatures you control have "{T}: Add one mana of any color."

Two-Headed Sliver

All Sliver creatures have menace. (They can't be blocked except by two or more creatures.)

Leeching Sliver

Whenever a Sliver you control attacks, defending player loses 1 life.

Screeching Sliver

All Slivers have "{T}: Target player mills a card."

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Striking Sliver

Sliver creatures you control have first strike. (They deal combat damage before creatures without first strike.)

Command Tower

City of Brass

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Galerider Sliver

Sliver creatures you control have flying.

Harmonic Sliver

All Slivers have "When this permanent enters the battlefield, destroy target artifact or enchantment."

Path of Ancestry

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.)

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Cultivate

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Mana Echoes

Whenever a creature enters the battlefield, you may add an amount of {C} equal to the number of creatures you control that share a creature type with it.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Darksteel Mutation

Enchant creature
Enchanted creature is an Insect artifact creature with base power and toughness 0/1 and has indestructible, and it loses all other abilities, card types, and creature types.

Cryptolith Rite

Creatures you control have "{T}: Add one mana of any color."

Metallic Sliver

Crystalline Sliver

All Slivers have shroud. (They can't be the targets of spells or abilities.)

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

The First Sliver

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)
Sliver spells you cast have cascade.

Sliver Queen

{2}: Create a 1/1 colorless Sliver creature token.

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
Ketria Triome enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Crypt Sliver

All Slivers have "{T}: Regenerate target Sliver."

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Root Sliver

This spell can't be countered.
Sliver spells can't be countered.

Muscle Sliver

Sliver Overlord

{3}: Search your library for a Sliver card, reveal that card, put it into your hand, then shuffle.
{3}: Gain control of target Sliver. (This effect lasts indefinitely.)

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Pulmonic Sliver

All Sliver creatures have flying.
All Slivers have "If this permanent would be put into a graveyard, you may put it on top of its owner's library instead."

Grand Coliseum

Grand Coliseum enters the battlefield tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Grand Coliseum deals 1 damage to you.

Zagoth Triome

({T}: Add {B}, {G}, or {U}.)
Zagoth Triome enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Ward Sliver

As Ward Sliver enters the battlefield, choose a color.
All Slivers have protection from the chosen color.

Synapse Sliver

Whenever a Sliver deals combat damage to a player, its controller may draw a card.

Blur Sliver

Sliver creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Swords to Plowshares

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

Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon, the Boundless enters the battlefield, choose a creature type.
Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

Indatha Triome

({T}: Add {W}, {B}, or {G}.)
Indatha Triome enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)