User blog comment:Jyggalag Daedric Prince of Order/Season 9 A Bust?/@comment-3519940-20130528025257/@comment-50.89.225.132-20130528192148

No, Gabriel and Anna didn't fall in the same way. Anna cut her grace out herself, which is how she became human (albeit one with telekinesis and junk). Gabriel and Metatron (and arguably Balthazar) just cut ties with Heaven and left for Earth without cutting out their grace, so they stayed fully-powered. Cass in S5 is so far the only fallen angel who lost ALL his powers just because he got kicked out of Heaven. Maybe he ranked lower than all the rest, so he needed to have that connection whereas it just gave Gabriel, Anna, Metatron, etc., a boost?

And I'm pretty sure it's not the same "spell." If it were, then ALL angels would've been cast out by it along with Lucifer.