I know this might be long but I just came up with it now and I think it makes sense-
If you look closely at the ten-tails’ eye, you can see that it is a combination of both the Rinnegan and the Sharingan. My theory is that long before, people didn’t have any jutsu at all (kind of like us) and all they had was taijutsu (but they didn’t call it that before because they didn’t have the jutsu system). The story states that long ago, the world was at war so people were probably using weapons like swords to fight instead of jutsu until the Sage of the Six Paths arrived. I think that the So6p started out first of all with normal eyes. Perhaps he was one of the few people to actually realize that humans had chakra and had started to use it for what would later become jutsu. One day, he accidentally came to find a sealing jutsu (similar to the fourth hokage’s) and then decided to go fight the terror of the world long ago, the ten-tails. Back then, the only thing able to use jutsu using its chakra was the ten-tails. The answer might have rested in its eye especially, the 9 tomoes. The Sage of the Six Paths then confronted the beast and finally, knowing he could defeat it, he decided to use his jutsu and seal the ten-tails to bring peace to the world and he decided to seal it within himself becoming the first jinchuriki. I think what happened then is that the So6p not only had the Rinnegan as he’s always shown with but also the Sharingan and he had the ability to change his eyes into either whenever he wanted. Once the ten-tails was inside him, he got its eye except it was split in two (the Rinnegan and Sharingan). 3 of the tomoes got infused into the Sharingan leaving 6, which he wore around his neck. That necklace was his secret to becoming the “God of Ninja”. Somehow, he used the tomoes to create the basic rules of jutsu and 5 of the tomoes became the 5 basic nature elements of chakra (Fire, Wind, Lightning, Earth and Water). The last tomoe became the power of genjutsu and humans had always had taijutsu so that explains the three types of jutsu. The So6p then had two sons, the older got the sages eyes and his spiritual energy and the younger son go his body and his physical energy. Meaning the older became the Uchiha and got his Sharingan and spiritual energy (Yin) and the younger got his powerful will and perhaps more of the sage’s amazing chakra went into the younger son (allowing them to get different chakra natures like the first hokage’s’ wood nature) and physical energy (Yang). Neither of them got the Rinnegan and I think that is because the secret to having the Rinnegan is both Yin and Yang chakra. If someone has both, the will attain the Rinnegan and Madara said he gave Nagato his Rinnegan so maybe he gave him Yin chakra while Nagato had Yang (he was an Uzumaki so he was a descendant of the So6p). I think the Sage of Six Paths was called that because he had six special abilities which made him godlike and if someone can get them, they’ll be godlike too. I think that’s what Madara’s aiming at. The six abilities could be- Yin chakra, Yang chakra, Wood Nature (because a bunch of people have the first hokage’s DNA in them), the power to control Biju (it would be pretty cool if someone could control the ten-tails like Killer Bee controls the eight-tails) and the last two might be Sharingan and Rinnegan cause I cant think of anything else.
If you look closely at the ten-tails’ eye, you can see that it is a combination of both the Rinnegan and the Sharingan. My theory is that long before, people didn’t have any jutsu at all (kind of like us) and all they had was taijutsu (but they didn’t call it that before because they didn’t have the jutsu system). The story states that long ago, the world was at war so people were probably using weapons like swords to fight instead of jutsu until the Sage of the Six Paths arrived. I think that the So6p started out first of all with normal eyes. Perhaps he was one of the few people to actually realize that humans had chakra and had started to use it for what would later become jutsu. One day, he accidentally came to find a sealing jutsu (similar to the fourth hokage’s) and then decided to go fight the terror of the world long ago, the ten-tails. Back then, the only thing able to use jutsu using its chakra was the ten-tails. The answer might have rested in its eye especially, the 9 tomoes. The Sage of the Six Paths then confronted the beast and finally, knowing he could defeat it, he decided to use his jutsu and seal the ten-tails to bring peace to the world and he decided to seal it within himself becoming the first jinchuriki. I think what happened then is that the So6p not only had the Rinnegan as he’s always shown with but also the Sharingan and he had the ability to change his eyes into either whenever he wanted. Once the ten-tails was inside him, he got its eye except it was split in two (the Rinnegan and Sharingan). 3 of the tomoes got infused into the Sharingan leaving 6, which he wore around his neck. That necklace was his secret to becoming the “God of Ninja”. Somehow, he used the tomoes to create the basic rules of jutsu and 5 of the tomoes became the 5 basic nature elements of chakra (Fire, Wind, Lightning, Earth and Water). The last tomoe became the power of genjutsu and humans had always had taijutsu so that explains the three types of jutsu. The So6p then had two sons, the older got the sages eyes and his spiritual energy and the younger son go his body and his physical energy. Meaning the older became the Uchiha and got his Sharingan and spiritual energy (Yin) and the younger got his powerful will and perhaps more of the sage’s amazing chakra went into the younger son (allowing them to get different chakra natures like the first hokage’s’ wood nature) and physical energy (Yang). Neither of them got the Rinnegan and I think that is because the secret to having the Rinnegan is both Yin and Yang chakra. If someone has both, the will attain the Rinnegan and Madara said he gave Nagato his Rinnegan so maybe he gave him Yin chakra while Nagato had Yang (he was an Uzumaki so he was a descendant of the So6p). I think the Sage of Six Paths was called that because he had six special abilities which made him godlike and if someone can get them, they’ll be godlike too. I think that’s what Madara’s aiming at. The six abilities could be- Yin chakra, Yang chakra, Wood Nature (because a bunch of people have the first hokage’s DNA in them), the power to control Biju (it would be pretty cool if someone could control the ten-tails like Killer Bee controls the eight-tails) and the last two might be Sharingan and Rinnegan cause I cant think of anything else.
