This explains–confirms–so many things, like how Oden's haki/soul/will was present in Enma and Scabbards blades. Why Kaido felt Oden's presence and got PTSD. It's clear that Oden's will/desire to kill Kaido was so strong that part of his essence remind in his blades. Plus, it explains the lore about the swords of dead strengthening them etc. How the black blades are actually created, the cursed blades and so many more. Unfortunately I don't have time to make a thread about it now.