User blog comment:Touchinos/“Proverbs 17:3” Discussion/@comment-31057575-20191115114219/@comment-108.36.76.116-20191120192952

They should not bind Death. Even if Death is Billie now, she is Death, and the other Death  told them what would happen if they ever tried to bind him again.

Weapon capabul of killing anything? How about Death's sythe? Anyone noticed how sythe's have appeared in Dean's hands a number of times. He has held Death's own sythe twice for sure, and something that looked a lot like it happened to be in Rufus's cabin in "Reading is Fundamental". Dean picked it up. In season 9, Dean picked it up again in "Captives", at the Castle storage unit. Yes, maybe it's a prop department joke, but maybe it follows Dean  around because he is destined to become the Death that reaps God. I do not put it past the writers to use little details, and turn them into huge plot twists that were sitting in plain sight, forgotten. Do you? And Dean did get some on the job training from the first Death. Why was that REALLY? This might account for it.