Keynome is a weird word; not even a word, if you go googling for it. Here's a few things I'm munging together that make neurons in my brain sparkle. Ten years ago, keynome was a phrase thrown about on rare occasions by programmers working on AI programs; it referred (in this layman's understanding), to objects that function as distillations of a larger "mindfile." As a term, it did not catch on. A keynote is the leading note in a musical key or chord. A genome is an organism's complete set of DNA, containing all the information needed to build and maintain that organism. In humans, the genome is contained in any cell with a nucleus. They're mentioned in the Deck of Villains as "fabled artifacts rumored to awaken the Starminds when reunited," which is something Concord would know ( sans context.) More prosaically, the Halcyon City Herald provides a custom move for fiddling with them that isn't for the faint of heart; let's just say the options on the list make it a good candidate for involvement in in whatever went down with the Quill/Chin "thing" a few years ago - I think it makes IC sense for Concord to draw that connection as more of the Sepiaverse "stuff" starts to come to light. If you want to think of them as the Masks equivalent of Infinity Stones, that's... close enough for cosmic math. Regardless of their real purpose, they can be mis used in similar ways.