What is this on the 10 tails Jinchuriki's hands?

[Sage6paths]

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As he tore through the two Hokages, he seemed be holding some sort of black weapon or jutsu.

Amaterasu kunai!?

 

[Bronze]

they are tailed beast blades

 

[-immortal-]

Bjuu blades

 

[Rasenman]

come on guys!...cant u come up with a better ame than that?

 

[Dantee]

I believe the correct term is Juubito-sticks.

 

[chopstickchakra]

Hashi and Tobirama were about to use "bringer of Darkness" jutsu when juubito ripped it out of their hands and now he is holding it like what you wanna do.