All Slivers have ", Sacrifice this permanent: This permanent deals 1 damage to any target."
All Slivers have ", Sacrifice this permanent: Prevent the next 1 damage that would be dealt to target player, planeswalker, or Sliver creature this turn."
(01/07/2013)
If the creature type of a Sliver changes so it's no longer a Sliver, it will no longer be affected by its own ability. Its ability will continue to affect other Sliver creatures.
(01/02/2007)
Note that the first ability can affect any kind of creature, but the second ability can affect only Slivers. Both abilities can affect players.
(01/07/2013)
Abilities that Slivers grant, as well as power/toughness boosts, are cumulative. However, for some abilities, like flying, having more than one instance of the ability doesn't provide any additional benefit.
