Board Thread:Theories and Speculation/@comment-810492-20170517190024/@comment-810492-20170517191557

Ravenlot 27 wrote: While the negative emotions theme of both this beast and the Zero-Tails really seem to be similar, as you pointed out by yourself, Zero-Tails isn't actually canon and even if it was, it still had been destroyed. Also, only the theme is similar, the appearance already differs (Zero-Tails looks like a leech while Boruto beast has the appearance of a Nue).

It's not like the anime has never taken characters and events from filler episodes though and integrated them into canon, so it's possible. The Zero-Tails wasn't actually confirmed to be destroyed though. According to the article on it, it was still in that sky castle ship when it crashed, but whether it was actually destroyed or not has not been confirmed. It's also possible it was sealed away too. So far in this anime, whenever it possesses someone, these flames seem to appear on some kind of seal. Whatever this creature is, it probably needs to absorb more negative energy for it to be fully released.

Also, if i'm not mistaken, in the movie, when someone is possessed by the Zero Tails, it just looks like they have a dark aura of chakra around them. The full appearance of the Zero Tails doesn't manifest until later on when it's fully released. We haven't seen the full appearance of this monster yet either since it appears to be sealed away for now.