Board Thread:Naruto Discussions/@comment-26388300-20150723025334/@comment-5273810-20150813030519

Uchiahmasters wrote: Rinnegan as it is IMO the stronger dojutsu and doesn't fade away after awhile (After Toneri's fight with Naruto Toneri's Tenseigan faded away and became a normal Byakugan implying that the Tenseigan is a temporary power up.) For all you know he can turn on and off his Tenseigan. If you are running low on chakra you might need to go to something that consumes less chakra(Byakugan).

You see it makes sense with the Rinnegan not being able to turn off as the Rinnegan that was being used by everyone(Madara's) is linked to Madara. You see with Uchiha the Sharingan is activated by a special chakra in the brain that is the reason you can turn on and off the Sharingan. Without it you can not turn off the Sharingan(example Kakashi with Obito's eye). As Madara was the one who awakened the Rinnegan it operated like his Sharingan and could only turn on and off(or switch to MS and Sharingan) with his Chakra.

Byakugan is different as anyone can turn on and off the eye's power with the only downside presumably being it consumes more from the use if they don't possess the Kekkei Genkai. The simple reason is the lack of the special chakra in the brain. This is also the reason why all Hyuga are born with the Byakugan and why not all Uchiha awaken the Sharingan.

As this difference exists between Sharingan and Byakugan(the "parent" ocular jutsus of the Rinnegan and Tenseigan shown) my theory is since that brain chakra does not exist from Tenseigan's base ocular jutsu that indeed you can turn off Tenseigan just like the Byakugan. I also theorize that the Rinnegan isn't inherently impossible for those without the Kekkei Genkai to turn off but is only that way if the Uchiha are the ones who awaken it.

For my theory on the Rinnegan if a Senju met the requirements and awakened it and another person acquired said eyes, you could turn it on and off at will just like any other ocular Kekkei Genkai shown. If you need the Sharingan eye then you transplant it like with normal Sharingan and just like with normal Sharingan transplants you can't turn the eye normal. Once the Senju has acquired the Rinnegan and loses the eyes the person who didn't awaken could according to my theory turn off the Rinnegan at will however he could not turn it lower than the Sharingan just like with normal Sharingan transplants.

So as you can see you assume to much on that account.