The Space Stone

The Space Stone does not count as a card in your
deck.
At the beginning of the game, exile The Space
Stone from your library face down.
At the beginning of your end step, you may lose 5
life. Then, if your life total is less than 10, put
The Space Stone face up onto the battlefield
under your control.
{1}{t}: Sacrifice The Space Stone: Creatures you control are unblockable.