User blog comment:B214/Talk About What You Want! 2/@comment-24409634-20140628103520/@comment-24409634-20140628143320

Sorry for the double post. The Wiki says otherwise.

"http://highschooldxd.wikia.com/wiki/Holy_Sword"

"The Holy Swords (聖剣 Seiken) are weapons infused with holy power, most of which were forged by the original God."

At least some of them.

My info comes from here, but you probably have the reason.