Disclaimer: I do not own Dragon Ball Z, or Naruto. They are owned by Akira Toriyama and Masashi Kishimoto respectively. I do not claim to own anything in this story.
"Hello, viewers," Kakashi greeted. He had to follow the same opening ritual of greeting the viewers - it was tradition at this point. "Welcome back to Piccolo and Kakashi on Theories, where today, we'll be focusing on my series once again. Finally."
"You seem excited, if only a little," Piccolo noted.
"And you wouldn't be? After all the talk about other series, finally we get to detail on mine again," Kakashi returned to his co-host. "So, today's episode is all about what if Naruto beat Sasuke at their first Valley of the End encounter."
"First of all, that fight was close. Perhaps the closest in the series - the first time watching, I believed that Naruto was going to win. They could end the series right there if that happened, but it did not happen. Good thing that this is what we are going to explore today."
"If Naruto defeated Sasuke, he would likely try to drag his friend back to Konoha, but would probably pass out due to his strength being incredibly exhausted by that point. That's when I and/or Sakura would come in and assist them."
Piccolo remained quiet, allowing the ninja to continue.
"Once we return Sasuke to the village, we would have to detain him for leaving the village in the first place and for wanting to join Orochimaru. Naruto would then have less of an incentive to train with Jiraiya for two years, as his original desire was to become strong to free Sasuke from the darkness. It's possible that he still would train with the Toad Sage."
"Sasuke might also be freed - if he were, he would be under close watch. Most likely by ANBU members, or by me. He would continue to be a member of the village and would most likely become good-hearted; his Curse Mark would probably be removed completely by this point. After noticing Naruto is training outside of the village and not wanting to be left in the dust, Sasuke would ask to be trained by me in a similar fashion. I'd accept, wanting to make sure Sasuke becomes a strong ally. That's when Part 1 ends and Part 2 starts."
"Part 2 is Shippuden, right?" Piccolo asked, to assure that his information was correct.
Kakashi nodded. "Yes, it is. Naruto returns to the village as normal and events pretty much stay the same from there on out, though with Sasuke on their side, major fights such as Hidan and Kakuzu, or Pain's Assault would likely end quicker. Sasuke and Naruto working together can prove to be a strong force, as evidenced by what they were capable of by the end of the Fourth Ninja World War in the original series."
"So overall, everything would stay the same, except for some fights and story arcs being finished quicker than usual?" Piccolo asked, summarising Kakashi's explanation.
"Essentially. Sasuke would be a great help for Konoha, even without his Curse Mark for the first few arcs. With training from me and his own determination to be better than Naruto, he might even unlock the Mangekyo Sharingan earlier. He'd still encounter Itachi as that was most of his focus during Part 1. Sasuke wouldn't let him go, so his focus on Itachi wouldn't change."
"That means the fight with Kaguya would be the final point of the series. Because Naruto and Sasuke are already friends by that point, there would be no need for their final fight, except to maybe prove who's really stronger," added Piccolo.
Kakashi seemed content. "And that's it for this episode, viewers. Piccolo and I will see you next time." The episode then ended.