Ten Tails: The Hidden Dangers.

In a plan to sabotage the hidden leaf village, the hidden mist village sealed isobu inside rin, hoping she would lose control of it and destroy the village. Rin opts to take her own life with the help of kakashi, and isobu is sealed inside yagura, who establishes a partnership with it. The latter having eaten its chakra fruit and later merged with the god tree in a battle against her sons, hagoromo and hamura. Prodigious as boruto might be, the 7th hokages son is far from. First appearing in naruto vol.

It is a titanic, nightmarish, demonic deity of unfathomable power who laid ruin over the world in the beginning of time.