Legions — Uncommon
Creature — Sliver
Root Sliver rulings:
10/4/2004 : The first ability applies when this card is not on the battlefield. The second ability applies when this card is on the battlefield.
4/1/2008 : The addition of “by spells or abilities” to the second ability is so that tribal instant or sorcery spells that happen to be Slivers (such as Crib Swap) can be countered by the rules if all of their targets become illegal.
7/1/2013 : 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.
7/1/2013 : 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.