Bonescythe Sliver

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

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

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

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Equipped creature gets +1/+1 for each other creature you control that shares a creature type with it.
Equip {2}