Shifting Sliver

Slivers can't be blocked except by Slivers.

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.

Blasphemous Act

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

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Phyrexian Arena

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

Muscle Sliver

Mystic Monastery

Mystic Monastery enters tapped.
{T}: Add {U}, {R}, or {W}.

Amoeboid Changeling

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.

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Savage Lands

Savage Lands enters tapped.
{T}: Add {B}, {R}, or {G}.

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.)

Ignoble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {B}, {R}, or {G}.

Canopy Vista

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

Rockfall Vale

Rockfall Vale enters tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Intruder Alarm

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters, untap all creatures.

Jungle Shrine

Jungle Shrine enters tapped.
{T}: Add {R}, {G}, or {W}.

Basal Sliver

All Slivers have "Sacrifice this permanent: Add {B}{B}."

Quick Sliver

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

Sliver Gravemother

The "legend rule" doesn't apply to Slivers you control.
Each Sliver creature card in your graveyard has encore {X}, where X is its mana value.
Encore {5} ({5}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Root Sliver

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

Stormcarved Coast

Stormcarved Coast enters tapped unless you control two or more other lands.
{T}: Add {U} or {R}.

Synapse Sliver

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

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Spelunking

When Spelunking enters, draw a card, then you may put a land card from your hand onto the battlefield. If you put a Cave onto the battlefield this way, you gain 4 life.
Lands you control enter untapped.

Sentinel Sliver

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

Frontier Bivouac

Frontier Bivouac enters tapped.
{T}: Add {G}, {U}, or {R}.

Heart Sliver

Crypt Sliver

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

Sandsteppe Citadel

Sandsteppe Citadel enters tapped.
{T}: Add {W}, {B}, or {G}.

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}.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Command Tower

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

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

Sol Ring

Manaweft Sliver

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

Necrotic Sliver

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

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters tapped unless you control two or more basic lands.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Shipwreck Marsh

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

Wood Elves

When Wood Elves enters, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Harmonic Sliver

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

Dormant Sliver

All Sliver creatures have defender.
All Slivers have "When this permanent enters, draw a card."

Pact of the Serpent

Choose a creature type. Target player draws X cards and loses X life, where X is the number of creatures they control of the chosen type.

Llanowar Elves

Mountain

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.)

Nature's Lore

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

Island

Crystalline Sliver

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

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Chromatic Lantern

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

Bonescythe Sliver

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

Cultivate

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.

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.)

Spiteful Sliver

Sliver creatures you control have "Whenever this creature is dealt damage, it deals that much damage to target player or planeswalker."

Forest

Overgrown Farmland

Overgrown Farmland enters tapped unless you control two or more other lands.
{T}: Add {G} or {W}.

Plains

Farseek

Search your library for a Plains, Island, Swamp, or Mountain 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."

Kindred Discovery

As Kindred Discovery enters, choose a creature type.
Whenever a creature you control of the chosen type enters or attacks, draw a card.

Swamp

Arcane Sanctum

Arcane Sanctum enters tapped.
{T}: Add {W}, {U}, or {B}.

Deserted Beach

Deserted Beach enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

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."

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.)

Galerider Sliver

Sliver creatures you control have flying.

Sliver Hivelord

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

Exotic Orchard

Arcane Denial

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.

Rogue's Passage

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

Crumbling Necropolis

Crumbling Necropolis enters tapped.
{T}: Add {U}, {B}, or {R}.

Three Visits

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

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Nomad Outpost

Nomad Outpost enters tapped.
{T}: Add {R}, {W}, or {B}.

Horned Sliver

Gemhide Sliver

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

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters tapped unless you control two or more basic lands.

Dreamroot Cascade

Dreamroot Cascade enters tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

Raise the Palisade

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

Explore

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

Counterspell

Elven Chorus

You may look at the top card of your library any time.
You may cast creature spells from the top of your library.
Creatures you control have "{T}: Add one mana of any color."

Arcane Signet

Biomancer's Familiar

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.
{T}: The next time target creature adapts this turn, it adapts as though it had no +1/+1 counters on it.

Syphon Sliver

Sliver creatures you control have lifelink. (Damage dealt by a Sliver creature you control also causes you to gain that much life.)

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.)

Capricious Sliver

Sliver creatures you control have "Whenever this creature deals combat damage to a player, exile the top card of your library. You may play that card this turn."

Sunken Hollow

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

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.)

Seaside Citadel

Seaside Citadel enters tapped.
{T}: Add {G}, {W}, or {U}.

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.)

Striking Sliver

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