Sliver Mastermind

+2: Until end of turn, Sliver Mastermind becomes a 5/5 Sliver creature with "Sliver creatures you control have Vigilance". It's still a planeswalker.
-X: Search your library for a Sliver creature with converted mana cost X, put it onto the battlefield tapped, then shuffle your library.
-10: You get an emblem with "If a Sliver enters the battlefield, copy its abilities that it produces and create an emblem with those copied abilities.