Should have seen it coming.
Kaguya.
Enemy.
Demon.
Monster.
Mother.
Hagoromo stared up at the baleful light of the moon. Into it, he had long sealed the corpse of the ten-tailed abomination that his mother had become. She who had eaten the fruit of the god tree, and gain the power of chakra. Unparalleled good could come from this new power, along with unparalleled evil.
When he had been young, it was all he could do to teach as many men as he could, to level the playing field and prevent the abuse of this power on the powerless. Now though, now he saw that teaching these people had led only to an even more terrible war then the one that his mother tried to end.
"Father! What are you doing outside?! You know you are ill." Hagoromo felt hands, strong hands, wrap themselves around his wrist and bring him to his feet. His eldest son was trying to bring him back inside of the little tent that they had pitched.
Hagoromo felt his heart ease for the love his son felt for him and his sibling. Yet, fear filled his heart. His eldest did not have the open hope and love that his brother carried, instead a firm belief that men must be shepherded by the strong, that by having knowledge and power one was entitled and responsible, that might made right. These feelings were the result of years of traveling with his father, and perhaps developing Hagoromo's powerful dojutsu. Perhaps, it was best, if his youngest was to receive his estate, and his eldest forge his own legend.
Hagoromo closed his eyes, the night and exhaustion and age taking over. He dozed off, his thoughts lingering, for a moment, on his mother, and tailed beasts, and the hope that one day, Princess Kaguya could descend from the moon, and walk the earth once again.
Was that such a terrible wish?
In Japanese mythology, Princess Kaguya descended from the moon
In Naruto, Princess Kaguya was sealed in the moon.
We really should have seen that one coming.