As the upcoming events in the manga will occur at the "bridge between heaven and earth" and as Kishimoto has already used many elements of the Japanese myths including the legendary sword Kusanagi (also called Ame no Murakumo no Tsurugi: "Sword of the heaven of the clustering clouds"), I think it is quite possible for the legendary spear Amenonuhoko to be featured. I don't remember any character handling a spear so it might be an opportunity to do so. If so called ninjas wield huge swords, why not spears? There might also be a pillar summoning technique, who knows... Which character do you think might use this weapon?