Breeding Pool

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

Darkheart Sliver

All Slivers have "Sacrifice this permanent: You gain 3 life."

Blood Crypt

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

Descendants' Path

At the beginning of your upkeep, reveal the top card of your library. If it's a creature card that shares a creature type with a creature you control, you may cast it without paying its mana cost. If you don't cast it, put it on the bottom of your library.

Haunting Voyage

Choose a creature type. Return up to two creature cards of that type from your graveyard to the battlefield. If this spell was foretold, return all creature cards of that type from your graveyard to the battlefield instead.
Foretell {5}{B}{B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Sliver Legion

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

Psionic Sliver

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

Cryptolith Rite

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

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Bonescythe Sliver

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

Sedge Sliver

All Sliver creatures have "This creature gets +1/+1 as long as you control a Swamp."
All Slivers have "{B}: Regenerate this permanent." (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Temple Garden

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

Overgrown Tomb

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

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Essence Sliver

Whenever a Sliver deals damage, its controller gains that much life.

Hibernation Sliver

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

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.

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.)

Galerider Sliver

Sliver creatures you control have flying.

Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Ancestral Vision

Suspend 4—{U} (Rather than cast this card from your hand, pay {U} and exile it with four 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.)
Target player draws three cards.

Sliver Queen

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

Sacred Foundry

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

Marsh Flats

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

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.)