[Theory] above Sharingan and rinnegan rinnegan byakugan the eye fusion true eye.

[sexywave]

maybe the final upgrade is a fusion of all three eyes to unlock a new with power that the other eyes powers look like garbage, Sharingan is yang and byakugan yin and rinnegan is wuji .all three most combine to recreate the true eye which will represent taiji a new eye with all the other three powers but at a higher level along with new powers.

 

[Edward]

I've always thought of it, but I never thought of a new powerup.

 

[sexywave]

Seeing the future,warping reality through your eye sight. Thermal vision eye summoning of elemental creature.

 

[vandell]

this could really happen

 

[FemmeFatale]

I've thought of that but it wouldn't be as natural as the Senju's power up. And I think that the rinnegan is most likely the most powerful eye because if there was another one then the sage will be surpassed (in doujutsu)

 

[OfficialRikudouSennin]

If your doing theories please use logic. :|