Island

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Steam Vents

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

Temple Garden

({T}: Add {G} or {W}.)
As Temple Garden enters, you may pay 2 life. If you don't, it enters tapped.

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.

Winged Sliver

Basal Sliver

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

Negate

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."

Sliver Hivelord

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

Cautery Sliver

All Slivers have "{1}, Sacrifice this permanent: This permanent deals 1 damage to any target."
All Slivers have "{1}, Sacrifice this permanent: Prevent the next 1 damage that would be dealt to target player, planeswalker, or Sliver creature this turn."

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.

Farseek

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

Mountain

Swamp

Gemhide Sliver

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

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

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.)

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.)

Gilded Lotus

Thought Vessel

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

Shifting Sliver

Slivers can't be blocked except by Slivers.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Hive Stirrings

Create two 1/1 colorless Sliver creature tokens.

Harmonic Sliver

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

Make a Stand

Creatures you control get +1/+0 and gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Cleaving Sliver

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters, you may pay 2 life. If you don't, it enters tapped.

Crypt Sliver

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

Fury Sliver

Manaweft Sliver

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

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Blur Sliver

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

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Tempered Sliver

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

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters, you may pay 2 life. If you don't, it enters tapped.

Commander's Sphere

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

Spinneret Sliver

Sliver Legion

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

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Quick Sliver

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

Mana Vault

Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

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.

Hibernation Sliver

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

Kodama's Reach

Horned Sliver

Shadow Sliver

All Sliver creatures have shadow. (They can block or be blocked by only creatures with shadow.)

Plains

Predatory Sliver

Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon, the Boundless enters, 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.

Might Sliver

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Vampiric Sliver

All Sliver creatures have "Whenever a creature dealt damage by this creature this turn dies, put a +1/+1 counter on this creature."

Psionic Sliver

All Sliver creatures have "{T}: This creature deals 2 damage to any target and 3 damage to itself."

Reliquary Tower

Megantic Sliver

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

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.

Dark Ritual

Stomping Ground

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

Galerider Sliver

Sliver creatures you control have flying.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters, you may pay 2 life. If you don't, it enters tapped.

Doom Blade

Synapse Sliver

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

Doubling Cube

{3}, {T}: Double the amount of each type of unspent mana you have.

Mindlash Sliver

All Slivers have "{1}, Sacrifice this permanent: Each player discards a card."

Forest

Distant Melody

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

Steelform Sliver

Arcane Signet

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

Sol Ring

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.

Lymph Sliver

All Sliver creatures have absorb 1. (If a source would deal damage to a Sliver, prevent 1 of that damage.)

Infernal Grasp

Destroy target creature. You lose 2 life.

Swords to Plowshares

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

Ward Sliver

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