I know I'm a little late to the ship on the SWT, but I think that they are so freaking cool, and I'm trying to piece together which ones have come up in-universe.
There is a blurb in one of the posts in Book of the Losts that mentions a rumor that Nightmare, leader of the Halloweeners, has come into possession of a card. Page 111 in Forbiden Arcana has notes from Ordo Maximus on several artifacts, and they mention this one being obtained from the Halloweeners "in exchange for item 6WT-PG."
So in additions to the ones already mentioned in Book of the Lost, I think it's safe to say that Nightmare has the Page of Blades.
