Mana Echoes

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

Forest

Virulent Sliver

All Sliver creatures have poisonous 1. (Whenever a Sliver deals combat damage to a player, that player gets a poison counter. A player with ten or more poison counters loses the game.)

Terramorphic Expanse

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

Hibernation Sliver

All Slivers have "Pay 2 life: Return this permanent to its owner's hand."

Fury Sliver

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Door of Destinies

As Door of Destinies enters, 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.

Reflections of Littjara

As Reflections of Littjara enters, 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.)

Island

Unclaimed Territory

As Unclaimed Territory enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Tempered Sliver

Sliver creatures you control have "Whenever this creature deals combat damage to a player, put a +1/+1 counter on it."

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.)

Bladeback Sliver

Hellbent — As long as you have no cards in hand, Sliver creatures you control have "{T}: This creature deals 1 damage to target player or planeswalker."

Explore

You may play an additional land this turn.
Draw a card.

Muscle Sliver

Bonescythe Sliver

Sliver creatures you control have double strike. (They deal both first-strike and regular combat damage.)

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Bonesplitter Sliver

Search for Tomorrow

Search your library for a basic land card, put it onto the battlefield, then shuffle.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with two 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.)

Path of Ancestry

Path of Ancestry enters 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.)

Quick Sliver

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

Brood Sliver

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

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

Hive Stirrings

Create two 1/1 colorless Sliver creature tokens.

Thorncaster Sliver

Sliver creatures you control have "Whenever this creature attacks, it deals 1 damage to any target."

Plains

Opaline Sliver

All Slivers have "Whenever this permanent becomes the target of a spell an opponent controls, you may draw a card."

Arcane Signet

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

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.

Dregscape Sliver

Each Sliver creature card in your graveyard has unearth {2}.
Unearth {2} ({2}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Command Tower

Evolving Wilds

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

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Venom Sliver

Sliver creatures you control have deathtouch. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it.)

Predatory Sliver

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.

Gemhide Sliver

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

Constricting Sliver

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

Battering Sliver

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 in a random order.)
Sliver spells you cast have cascade.

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.)

Reclaim

Put target card from your graveyard on top of your library.

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Cleaving Sliver

Homing Sliver

Each Sliver card in each player's hand has slivercycling {3}.
Slivercycling {3} ({3}, Discard this card: Search your library for a Sliver card, reveal it, put it into your hand, then shuffle.)

Harmonic Sliver

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

Prismatic Lens

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

Lavabelly Sliver

Sliver creatures you control have "When this creature enters, it deals 1 damage to target player or planeswalker and you gain 1 life."

Cultivate

Lancer Sliver

Sliver creatures you control have first strike.

Blur Sliver

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

Sentinel Sliver

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

Farseek

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

Etchings of the Chosen

As Etchings of the Chosen enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{1}, Sacrifice a creature of the chosen type: Target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Sol Ring

Spined Sliver

Whenever a Sliver becomes blocked, that Sliver gets +1/+1 until end of turn for each creature blocking it.

Mountain

Battle Sliver

Eladamri's Call

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

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Mesmeric Sliver

All Slivers have "When this permanent enters, you may fateseal 1." (To fateseal 1, its controller looks at the top card of an opponent's library, then they may put that card on the bottom of that library.)

Nature's Spiral

Return target permanent card from your graveyard to your hand.

Diffusion Sliver

Whenever a Sliver creature you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.

Two-Headed Sliver

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

Bring to Light

Converge — Search your library for a creature, instant, or sorcery card with mana value less than or equal to the number of colors of mana spent to cast this spell, exile that card, then shuffle. You may cast that card without paying its mana cost.

Necrotic Sliver

All Slivers have "{3}, Sacrifice this permanent: Destroy target permanent."

Hollowhead Sliver

Sliver creatures you control have "{T}, Discard a card: Draw a card."

Swamp

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Leeching Sliver

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

Sinew Sliver

Striking Sliver

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

Congregation at Dawn

Search your library for up to three creature cards, reveal them, then shuffle and put those cards on top in any order.