Revenge of the Otsutsuki

He was born as youngest child of Minato Namikaze and Kushina Uzumaki on night of Kyuubi's attack. Kyuubi was sealed into his older siblings Arashi and Mito and Konoha sometime later rebuilt herself. Naruto, Arashi and Mito trained together, but his parents, Jiraiya and Tsunade told Naruto since he was the youngest, he will be one to serve Arashi and Mito as they are future heads of Namikaze and Uzumaki clans and Naruto accepted that. When he awakened Rinnegan, Tsunade extracted his eyes and put one in Arashi and other in Mito, while he got their normal eyes. His entire life, he looked at world with eyes which weren't his.

Even if he was strong, everyone treated him as servant of Namikaze and Uzumaki clans.

In the end, in fight with Goddess Kaguya, they were losing and Naruto used Shiki Fujin to seal Kaguya into himself and thus lost his life in process as technique required life of user.

His soul entered Throne of Heroes and floated through dark dimension with nothing in sight while Kaguya was his only companion. As she was Goddess of Chakra, she could see everything what was happening on mortal plane as long as humans wield chakra.

During that entire she would show him what she is seeing.

Peace reigning through Elemental Nations with five villages now acting as friends and allies. There was no more hate. And at that, Naruto didn't feel anything.

She showed him that Arashi and Mito were celebrated as heroes and put in history, while he was also put in it, but as some side character.

But then she showed him Arashi, Mito and all their friends getting married as they lived happy lifes. And for the first time in his life, Naruto felt envy.

She showed him birth of Arashi's and Mito's first children with them, Minato, Kushina, Jiraiya, Tsunade and all villages celebrating it.

She showed him peaceful deaths they had and in that moment something snapped in Naruto. Jealousy, hatred and most importantly rage took over him!