u/The5thexclamationmrk

so, in Magic Bites we discover that only bone can kill an upir, and we go through a bunch of hassle to steal the dragon bone the eventually kills it.

but eventually we learn that Kate's sword is actually made from her grandmothers bones... does that mean it would have killed the upir all along??? Or, does all the magical transformation and "metal"-like quality of the bones of her grandmothe mean it would count as metal and be ineffective? Thoughts?