Ninestrike is a weapon that is used by Ninetails in its true form and in Evil Rao guise. The weapon is capable of slashes and stabs, as well as a devastating charged slash. Ninestrike, although bearing a "divine" (or demonic) appearance, is just made of normal metal and alloys, which makes it vulnerable to Thunderstorm. Amaterasu took advantage of this in her battle against Ninetails.
The sword is originally used by Ninetails, but Lechku & Nechku can summon it as one of their attacks and Yami's fourth form's arms can turn into two imitations of this weapon. However, the sword is not obtained after Ninetails's defeat and is seemingly destroyed with it.
- Ninestrike has a brush dipped in crimson ink at the pommel, like Denkomaru, but Ninetails is never shown to use this brush to interfere with Amaterasu's Celestial Brush techniques. What Ninetails used to interfere was his central tail, similar to how Amaterasu used the Celestial Brush.
- In the center of the Underground Ruins, a Ninestrike-like lightning rod receives the lightning generated from the Thundercloud and powers the lightning-based security system of the entire ruins.
- Much like the Seven Strike glaive, Ninestrike appears to be designed after the Seven-Branched Sword, a decorative blade gifted to a Yamato ruler in Japan by the king of the Baekje kingdom, Korea, in 252 AD. Ninestrike, however, adds in an extra prongs at the side, increasing the total number of branches (counting the center blade) to nine as a means of tying in with Ninetails' name and species.