My theory how uchiha had the sharingan
When So6p divided the ten tails into 9 tailed beast
The eyes of the Ten tails are combined sharingan and rinnengan
The sharingan must have been divided to into an uchiha baby
Having the first sharingan uchiha
When So6p divided the ten tails into 9 tailed beast
The eyes of the Ten tails are combined sharingan and rinnengan
The sharingan must have been divided to into an uchiha baby
Having the first sharingan uchiha