Herald Of Lifeforce

Flash; Convoke
If you convoked this Herald Of Life force with
four or more creatures, search your library for
the Leyline Of Lifeforce and put it in the battlefield. Shuffle your library.
As long as you control Leyline Of Lifeforce, creatures you control can't be exiled or sacrificed,
and creatures can't enter the battlefield from
any player's graveyard.