User blog comment:Fusedtwilight/Season 9 plot/@comment-174.49.83.252-20130516203034/@comment-3045936-20130516204228

Very good points. After all only Castiel became human (By what Metatron said). But, even Naomi said the spell was to Banish all angels from Heaven. That doesn't automatically mean turn human. After all angels need the connection to return to heaven, even the Archangels according to the many interviews with Eric Kriple, say to explain why Lucifer didn't just return to heaven once release.

(However, that makes it hard to understand how Castiel could when technically he shouldn't have be able to, as he was still a fallen angel at the end of season 7. Unless, Naomi fixed his connection to heaven after her squad saved him.)  And, Naomi said Metatron wanted to do what God had done to Lucifer meaning expel from heaven.

As, to angels on the Earth, we know that overtime an angel can be weakend to human status, if the connection is broken. Also, that brings up another question, does angels become human souls, if they lose their grace?