Zyx, Called From Rest

Zyx, Called After Rest is treated as though
he does not exist unless he's been called.
Call {w}{w/b}{b} (This permanent becomes
called).
Returning, doublestrike, vigilance, lifelink, and
saving 4 (At the end of your turn return four creatures or planeswalkers from
the graveyard to the battlefield under your
control.
"Zyx, though you rest, another world needs your
help."