Manaweft Sliver

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

Sinew Sliver

Unclaimed Territory

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.

Leeching Sliver

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

Collected Company

Look at the top six cards of your library. Put up to two creature cards with mana value 3 or less from among them onto the battlefield. Put the rest on the bottom of your library in any order.

Ancient Ziggurat

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

Plains

Gemhide Sliver

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

Island

Mountain

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Sliver Legion

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

Aether Vial

At the beginning of your upkeep, you may put a charge counter on this artifact.
{T}: You may put a creature card with mana value equal to the number of charge counters on this artifact from your hand onto the battlefield.

Forest

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.

Realmwalker

Changeling (This card is every creature type.)
As this creature enters, choose a creature type.
You may look at the top card of your library any time.
You may cast creature spells of the chosen type from the top of your library.