St. Basil/ Gregory of Nyssa does not say this:
All the angels, having but one appellation, have likewise among themselves the same nature, even though some of them are set over nations, while others of them are guardians to each one of the faithful.
It does not exist. I don't care how many websites quote this, or if it's in italics. They may say it's in Against Eunomius, book 3, first part...but it's not. It doesn't exist. It's a lie! St. Basil never said this. EVER!
I've spent hours looking through (what I thought was) original source material. Guess what? The quote is nowhere in there.
And then, there's this tidbit from a very old book that everyone takes on faith:
He says, at the beginning of his 3 Book against Eunomius, that all the angels have indeed the same name, and are of the same nature; but that some preside over whole nations, and others take care of every faithful person. Now, as much as a whole Nation is to be preferred before a single man, so much is the dignity of an angel committed over a whole nation, above that of another angel, who has only the keeping of a single person.
Yeah, that doesn't exist. I've spent quite a while looking for both of these quotations, and I'm quite convinced they're made up. Perhaps they state fact, but I see NO evidence of St. Basil saying them at all.