Gemhide Sliver

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

Sliver Legion

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

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.

Manaweft Sliver

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

Sliver Hivelord

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

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.

Quick Sliver

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

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Two-Headed Sliver

All Sliver creatures have menace. (They can't be blocked except by two or more creatures.)