Fuulm, Reaped From Blackdepths

Each time you surveil, put cards you put into
your graveyard into a separate pile. Fuulm's
power and toughness is equal to those cards in
that pile. That pile acts as a second graveyard.
Cards in that graveyard can't be exiled from
there.
Shield—{b} (You may pay this card's shield cost
anytime. If you do, Fuulm's base power and toughness
are 0/7 until end of turn.)