Setting: SI/OC insert
Starting time period: 22 before Canon starts
MC/OC/SI: Same age as Kakashi
Chakra nature: Wind, water
Fighting style: Kenjutsu, Fūinjutsu
Possible relationships: open
Concept idea:-
OC/SI is reborn as an Uzumaki child whose parents were able to flee Uzushiogakure when it was destroyed, eventually ending up in the Iron and gained sanctuary with the Samurai where our story eventually begins.
Growing up in the land of Iron, our OC would naturally learn Kenjutsu of the Samurai, while also learning Fūinjutsu from his parents, his mother is a skilled master of such and was one of the reasons the samurai happily took them in.
With his Uzumaki Heritage he would come to become a young master of Fūinjutsu, before leaving the land of Iron to take advantage of his knowledge of canon to change things for the better.
Arriving in the land of fire just days before he arrives in time to prevent Kushina and Minato's death at the claws of the Kyūbi, sealing half the chakra into Naruto and the other half into Kushina to keep her from dying and preventing Minato from sacrificing his life needlessly.
Returning to Konoha with them, he appeals to Minato as the 4th Hokage to allow him to reform the Uzumaki clan as one of Konoha's clans, demonstrating his skills and showing how it would benefit Konoha, something that Kushina was all for.
Future:
Konoha advances rapidly with new seals created by the Uzumaki clan in various ways
Naruto has family growing up
Kushina eventually befriends Kurama and gains chakra mode
Various Uzumaki are found and brought to Konoha to rejoin the clan
Karin Uzumaki and her mother rejoin from Kusa during the Chunin exam later