Is there a single word that means "blade within a blade"? It doesn't have to be "blade" specifically, but anything sharp (i.e. "knife within a knife", "dagger within a dagger", "[sharp object] within a [sharp object]").
Not certain if this is a valid geometric phenomenon, but the desire for such a word exists.
I'm also open to wordplay. The word itself doesn't have to formally exist, so long as its meaning is easily understood.
The blade of a greatsword is smashed. Within the debris was a smaller dagger; a blade within a blade; a(n) [word I'm looking for].