Andromedus

Is it possible that silver absorbs and stores investiture, kind of like a battery. For example, with the cognitive shadows on Threnody, the silver begins absorbing and destroying the shadow, so they run away. However, the investiture is stored in the silver. Then, Nightblood's sheath can be silver that is full of investiture. Maybe later there will be a method of removing investiture from silver, akin to how a feruchemist stores investiture in nicrosil.