A crystal that you picked up in the ruins after completing the duel against The Knave.
The already-cooled blood and fire still maintain the shape of a feather, that is framed with solidified sleek black threads.
Before their thoughts have matured, young children are reliant on the meticulous care of their parents, just as fledglings need the aegis of an adult wing. But young birds too will one day spread their now-abundant plumage and fly away for more distant skies. Such is life, and such is fate.
It is to fulfill such wishes that "Father" wove dangerous spider-silk into a facsimile of feathers, that she might grant her family some warmth.