[Naruto Fanfiction + Sharingan + Survival in a Time of Chaos + Some Original Plot Elements + Collecting Kekkei Genkai + Collecting Tailed Beasts + Collecting Sage Bodies + Developing Kekkei Tota]
A shut-in is watching the Naruto anime at home when he accidentally transmigrates into one of Orochimaru's experimental subjects, a hybrid of the Uchiha and Uzumaki clans. Danzo plants him in the Uchiha clan and names him Uchiha Jaku.
The story takes place before the Third Shinobi World War. From merely surviving to growing powerful, Uchiha Jaku gradually changes the course of the original story, saves characters who were originally destined to die, and builds a new utopia of his own.
He possesses a unique Mangekyo Sharingan: his left eye seals ninjutsu, while his right eye steals Kekkei Genkai.
The Uzumaki bloodline in his body awakens a talent for sealing techniques. He creates a variety of seals, and his body is even more compatible with Hashirama's cells.
There is no system, and most of the whole story will stick to the original work, but the time of the original drama is very close, so the original time will be stretched out a bit to allow the protagonists to have time to experience it.