Steelform Sliver

Jumpstart: Historic Horizons

"Though the slivers may sometimes resemble us, they are not human. Anyone who fights them must remember this."
—Sarlena, paladin of the Northern Verge

Magic 2014

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.

If you change the creature type of a Sliver you control 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 you control.