Harmonic Sliver

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

Two-Headed Sliver

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

Sliver creatures you control have deathtouch. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it.)

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

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

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

Sliver creatures you control have flying and haste.

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

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

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

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