Disclaimer: I don't own Naruto
-Three Years Later-
It had been three years since Obito had left his son Izuna in the hands of a Zetsu clone. He had monthly updates from Zetsu about his son's safety and condition. Obito was actually a little confused. When he was young he always thought he would be able to stand being away from his family. Growing up an orphan he didn't really know what a family was. He just assumed that the love of family develops over time, since he hadn't spent any time with his son, that's why he doesn't miss him.
Nagato had finally come to meet with Obito. It wouldn't be much longer until he was able to leave most of the work for Nagato to handle. He would have to hurry Izuna's training needed to start in the next few years. Obito had been going nonstop for almost ten years, soon he would be able to relax a bit.
-Two Years Later-
Obito had finally finished teaching Nagato the Rikudō Jutsu. Even though he was a cripple he could now project his will into avatars that he could control. He called them his Six Paths of Pain, they couldn't go too far from Nagato and they each carried only one of the six paths of the Rikudō Jutsu.
Obito was now able to return to the village Izuna was staying in. Zetsu had once asked him why he wanted the boy raised in a civilian village instead of in the hideout. Obito's only reply was that he would need the Mangekyō one day.
Obito appeared from a vortex in front of a small house, which the clone had made with its Mokuton jutsu. It wasn't much just a small two bedroom house a little outside the village. Close enough for Izuna to make friends but far enough for him to train without drawing attention to them.
As Obito walked through the front door he saw a small black haired boy sitting at the kitchen table eating his lunch.
"We'll be starting your training today, after you finish eating." Obito said as he sat opposite the boy at the table. When the boy heard this, his head shot up and he had a gleam in his eye. Izuna had been begging the clone to start his training for months. He knew from a young age that he was one of the few remaining members of the Uchiha Clan.
"Really!" the boy yelled excitedly.
Obito told him to finish eating, and he'd never seen food disappear so fast before. As soon as he was done the boy was standing in the back yard waiting for instructions. While Obito was pleased with his enthusiasm, he would have to calm the boy down or something similar to what happened to him would happen to the boy.
"Okay, first off physical training. It doesn't matter what you know about being a shinobi if you can't move your dead." The boy gulped and nodded. Obito couldn't help but notice the similarities between the two of them. "Run around the edges of the clearing until I tell you to stop." And just like that his training started.
-Five Years later-
Izuna had come far in the last five years. His father had taught him a lot, and though he hadn't activated his sharingan yet, he knew he was strong. Today was his tenth birthday and his father had promised him something really special as a gift.
As Izuna was finishing up his morning workout, he noticed someone was watching him. The man's skin was completely white. The only color Izuna could see was his green hair. When the man noticed he'd been spotted he ran at the boy with a kunai in his right hand.
Izuna saw the kunai and thought of calling for his father, but he had never fought someone other than his dad and wanted to test his strength. He would impress his father by dealing with this guy by himself.
The man swung the kunai at the boy's throat; the boy leaned back and kicked him in the stomach. The man caught his foot and threw Izuna into a nearby tree. Izuna flew through the air and his right shoulder hit a tree. There was a loud snap and Izuna screamed. His shoulder was dislocated.
Lying on the ground, feeling real pain for the first time in his life, he was a little disoriented. He had been injured in his spars with his father but he'd never broken any bones. He was wondering where his dad was, surely he heard him scream, they weren't that far from the house.
'Maybe he killed dad first.' Izuna thought starting to panic. 'I have to get up, keep fighting.'
Izuna stood up holding his right arm with his left. His attacker pulled his right arm back and threw the kunai. Izuna dodged to left into the path of another kunai he hadn't noticed. The kunai struck his left shoulder, and his arm dropped limp.
The man charged ahead at full speed with another kunai in hand. Izuna turned and ran toward the house. Dodging the kunai his attacker was throwing, one he missed sliced through the back of his right knee. Izuna collapsed and rolled onto his back, the man was still charging.
All Izuna could do was sit and watch as his would be killer drew nearer. When the man was only ten feet away things changed. His vision sharpened and the man's movements seemed to slow down a little bit.
As the kunai was swinging down to take Izuna's life the man looked him in the eye. As the boy was closing his eyes Zetsu noticed that the boy had unlocked his sharingan. Zetsu stopped the kunai.
When Izuna noticed the lack of pain he slowly opened his eyes. He saw his attacker standing a few feet away from him smiling at him. Then his father appeared using his Kamui.
"Happy birthday Izuna-kun." Said the man who attacked him. Izuna just stared at him like he was crazy.
"Yes, happy birthday. My gift to you was your first true taste of combat against an enemy attacking with killing intent." Izuna was baffled his father had set all this up. "You also unlocked your sharingan. Now your real training can begin." And begin his training did, nothing he'd done before this was near as intense.
By the time Izuna was twelve his father had him hunting B-Rank Missing Nins for combat experience. His father told him that soon he would be ready for the next level of the sharingan. This surprised Izuna because he'd never known there was another level.
Now he was about to go on his first mission with his father. They were going to collect the bounty on Sharingan no Kakashi an A-Rank Shinobi from Konoha. Zetsu reported that Kakashi was taking his team of genin on a C-Rank mission to wave country. This was going to be fun.
Chapter two is done next chapter will feature Izuna and Obito against Kakashi and his Genin. I don't have a beta or know how to get one so I apologize for errors.