In the Mattins hymn for the Feast of the Miraculous Medal on 27 November, we find the stanza Numisma quos ornat tuum/ Fove benigno lumine;/ Virtus sit inter proelia/ Aegis in hostes praepotens. (Those whom thy Medal adorns,/ Foster with kindly Light;/ May they have strength among their battles/ And may the Aegis be mightily powerful against their enemies.) Yes ... the second of those two lines might get you thinking ... but I want to concentrate on the Aegis: a regular piece of kit when Greek Gods open hostilities. Here is a modified version of a note on the Aegis by Professor Christian Fordyce of the University of Glasgow (founded by Pope Nicolas V in 1451 long before people learned to read or write in Edinburgh).
"Two different conceptions of the divine aigis appear in Homer--the result, probably, of the concurrence in the word of two homonyms, the one meaning 'hurricane', the other 'goat-skin'--and Virgil has taken over both. In Homer the aegis of Zeus is something which he takes up and brandishes in his hand to dismay mankind: it is dark, like the storm-clouds, and it was made for him by Hephaestus (Vulcan) the bronze-smith: so Apollo, when he has it, takes it in his hand to shake. The hurricane is represented as a weapon wielded by the god. That is clearly Virgil's picture of Jupiter's aegis at Aeneid VIII 354, where nigrantem and concuteret translate Homer. But elsewhere the aigis of Zeus is not dark but radiant and it is fringed, and that picture is elaborated when Athena (Minerva) has it: it seems to be conceived as something worn, with a tasselled fringe and with the Gorgon's head on it: she throws it about her shoulders and Ares (Mars) strikes her on it: so in Aeschylus the words suggest a garment hanging from the shoulders and filling with the wind. This is the form taken by representations of the aegis in art, where it is a sort of breast-armour bearing the Gorgon's head in the centre, surrounded by wreathed snakes (so it was in the Parthenon statue) and this is the aegis which Virgil describes as being made for Pallas by the Cyclopes."
The dominant imagery is of our Enemies being thoroughly terrified ... it will make their hair stand on end (horrifica). Remember that Papa Pecci was a Classicist!