Call of Ancestors

When Call of Ancestors enters the battlefield,
exile all creatures, then move them and Call of
Ancestors to Spirit Realm (In Spirit Realm zone creatures lose all abilities and become 2/2 spirits. Creatures within the zone can still attack as usual
and they can block only other creatures in the zone. Permanents within the zone can't be affected with
spells, abilities or permanents that are not in the zone)
Any player may pay {4} or {w}{w} to either return
a creature back from the Spirit