Ninetails raising Ninestrike
It plays a great role in Amaterasu's battle with Ninetails as it is one of the mediums through which Ninetails can attack and the only Weapon is uses. It is also Ninetails' weakness during the battle as its metallic composition is very vulnerable to electric attacks. Amaterasu can use Thunderstorm to direct lightning, from one of Oni Island's many thunderclouds, to the glaive to shock and stun Ninetails. Upon the death of Ninetails, it will disappear and is therefore unobtainable. Ninetails uses it to stab and slash at Amaterasu but can also deal a devastating charged slash.
It greatly resembles Amaterasu's Seven Strike. However, Lechku and Nechku can summon it during their battle with Amaterasu and Yami's third form wields similar weapons. This seems to suggest it was a replica of a Divine Instrument given to Ninetails by Yami and follows with the idea that a Ninetails with nine tails has achieved a state of godliness. This is much like Ninetails in the game who can wield the Brush Techniques of the Brush Gods and takes on the overall visage of a of god, including her own constellation, Celestial Markings and how the battle arena resembles the heavenly plain where Amaterasu meets the Brush Gods. The art book also comments how Ninetails considers itself to be a god.
It has a Celestial Brush on the hilt but Ninetails does not seem to use it, instead it uses its tails.
In the Underground Ruins, a statue of it appears and acts as a lightning conductor.