Cavern of Souls

As Cavern of Souls 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, and that spell can't be countered.

Crystalline Sliver

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

Heart Sliver

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.)

Crypt Sliver

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

Harmonic Sliver

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

Sliver Hivelord

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

Sinew Sliver

Quick Sliver

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

Manaweft Sliver

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

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.)

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.)

Commander's Sphere

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

Shifting Sliver

Slivers can't be blocked except by Slivers.

Predatory Sliver

Arcane Signet

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

Root Sliver

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

Spiteful Sliver

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

Sentinel Sliver

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

Secluded Courtyard

As this land 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 or activate an ability of a creature source of the chosen type.

Lazotep Sliver

Sliver creatures you control have afflict 2. (Whenever a creature with afflict 2 becomes blocked, defending player loses 2 life.)
Whenever a nontoken Sliver you control dies, amass Slivers 2. (Put two +1/+1 counters on an Army you control. It's also a Sliver. If you don't control an Army, create a 0/0 black Sliver Army creature token first.)

Muscle Sliver

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Command Tower

Syphon Sliver

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

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.

City of Brass

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

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

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.

Ancient Ziggurat

{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

Blur Sliver

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

Exotic Orchard

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

Chromatic Lantern

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

Patchwork Banner

As Patchwork Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.