Byakugan

The Byakugan is a Kekkei Genkai of the eyes that genetically belongs to the Hyuga Clan. Anyone who is capable of using the Byakugan can see almost anything they wish to see with it. It also allows them to see the inner chakra circulatory system, which they use to their advantage in their battle style Gentle Fist. Gentle Fist is a fighting sytle based on hitting chakra points which prevents their opponent from using chakra. The Byakugan has a 360 degree field of vision, making ambushes difficult to achieve.

Weaknesses
As powerful as it seems, the Byakugan has two weaknessess. At a certain point on the back of a Byakugan-user's neck, there's a blind spot, which is around the location of the thoracic vertebra. Anyone who manages to launch a projectile aimed directly at that particular point can evade detection, which may lead to the user's death. However, not many ninjas who fought Byakugan users manage to figure out this weakness in time. This weakness is covered up by the jutsu known as the Heavenly Spin, but the technique has its downfalls too. The other one is that the Byakugan is thermographic, causing difficulty if everything around is the same temperature, as Hinata Hyuga notes in the Bikochu arc.