Experiment A339: Failure.
Yes, the cloning of Uchiha cells into a multi-celled, free-thinking being was ultimately a failure.
For convenience sake, it was raised by another experiment, a woman. She was a noncombat, purely scientific exploration. Experiment A339 grew from infancy to be a kind, frightened little boy
The boy despised fighting so much, that when pitted against other trials, he would not react to beatings. He would sustain damage without giving any, pitifully waiting for the end. His left eye was destroyed in one such occurrence, infuriatingly enough. It left him with a long, thin scar from his forehead to the chin.
Orochimaru eventually gave up on the gradual approach and decided to do something abit more… …drastic.
The woman, who was called by other test subjects simply "Ai," was finally useful. She was brought into the fighting arena. Experiment A339 was forced to observe her termination.
As theorized, A339 gained a beginning form of the sharingan as result. And force was needed to remove him. Sedated, he wept in his cell for a surprising amount of time.
This was the first success in A339's history of existence.
He still would not react though, to Orochimaru's frustration, to any further environmental changes. Even less than before most of the time. Instead he was put on solo missions, these missions were designed to decommission him in the process. But so that the sharingan eye could be saved and stored for extensive testing.
But A339 showed a strange durability in the field and proved useful from time to time. He ran into a young boy, a little older than himself on one such mission.
That older boy was blonde and arrogant. He could not believe that the smaller boy had no name. So the older boy thought up a simple one on request, so that it could possibly be remembered through the extensive pain of testing.
Deidara thought up a cute name to match this shy, kind little boy…
Tobi.