Board Thread:Theories and Speculation/@comment-30355627-20161218164138/@comment-1512913-20161222093208

All I'm saying is there is no canonical proof that Rinnegan became Sharingan and that Sharingan can become Rinnegan, it was only an in-universe hypothesis, it's nowhere said as a fact, yet for some reason the fandom decided to think just that, even tough it's completely illogical.

There's the Rinne Sharingan...
 * even the term is a combination of Rinnegan-Sharingan
 * the appearance as well is a combination of Rinnegan-Sharingan
 * from it descended the Rinnegan and Sharingan

So it's completely impossible for Rinnegan to have become Sharingan and for Sharingan to become Rinnegan, they are not progression of each other, they are sibling doujutsu with same parent.

When you split Rinne Sharingan, you get Rinnegan and Sharingan. You don't get Sharingan but splitting Rinnegan. Likewise, when you combine Rinnegan and Sharingan back together, the result is a semi-Rinne Sharingan-like eye, as seen with Sasuke, he is a living evidence that Rinnegan and Sharingan aren't evolution/devolution of each other, but related sibling doujutsu with Rinne Sharingan as their parent.

If Rinnegan turned into Sharingan/Sharingan turned into Rinnegan, it wouldn't be possible to combine them, but it is and the result is almost a recreation of their parent.

There is like no proof whatsoever that what this wiki claims and so many fans falsely believe to be true, is actually true. The only factual evidence is nothing more than from a in-universe character's hypothesis, which we actually know not to be true.