Who here believes in this wonderful Legacy. From the Naruto manga, it is thought to be had by Zetsu and later be released that Neji has it as well
Original theory, by the great Ando.
Belivers of the amazing theory Golden Byakugan
"all that we can say about zetsu is: he eat people/he can move inside of things/can see in largest ranges/ he can see through things (Sasuke X Naruto fight)
so my theory start in the event that konoha send Hizashi's corpse to the cloud contry…in this ocasion the cloud kage saw that was impossible remove the byakugam
so he called a man who could absorve bloodlines, like a tree who can absorve minerals from the ground...a man called Zetsu the only survivor of his clan
in this ocasion Zetsu had eatean hizashi and manipulated the byakugam abilities that was sleeping in the corpse
he manipulated the cells breaking the seal and increased the hability of his doujutsu until a moster level called "Golden Byakugam"...so when he finish the job the cloud kage send his mans to kill zetsu to get Byakugam
but now he got the most motafuka bloodline, and then he had scaped killing hundreds of mans, moments later he enter in akatsuki
so i belive that Neji gonna fight against Zetsu and he will also activate the golden byakugam to avange his father...