The Byakugan is a doujutsu, which opens the user's eyes and with many abilities it is said to be formed around the sharingan and rinnegan. This doujutsu is one of the most powerful ones set to let the user see long distances as well as give access to the sacred and unique style of taijutsu known as Gentle Fist.
The byakugan came with this taijutsu as it uses the eye's abilities of rapidly hitting chakra points as Byakugan can see into the body and know chakra and if it's a clone or not. This ability is useful to learn Gentle Fist. It is unsure if Sharingan can copy this style as Gentle Fist seems to be a KG Ability to the user. When born the byakugan activates and will always stay activated.
The Byakugan can tire the user as it's abilititys can put a certain drain of chakra, that is why most byakugan users end there battle quickly by stopping the tenketsu flow. Taking all chakra away from the oppponent.
Neji, a expert within the Byakugan and Gentle Fist, proved even as a lower branch member he was able to use rotation. Neji when faced naruto also was able to see through most of his moves and dodge them while able to quickly see.
The Byakugan also has another ability, the 360 degree nearly pefect eye sight, only 1 small blindspot at back of neck, as Neji soon gave away the secret while facing one of the sound 4/5. This 360 degree vision is special because it gives the user near perfect vision to see when the opponent is going to attack.
The Byakugan is pretty equal to the Sharingan.
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