Board Thread:Naruto Discussions/@comment-26107879-20181004003653/@comment-34752936-20181204182120

Raikiri/Chidori causes a bit of tunnel vision due to the necessary speed involved. Without the perception powers of the Sharingan, it’s too easy for Kakashi to get counter-attacked. In short, he lacks the perception powers and reaction time to safely use his technique without the Sharingan.

The Fourth Raikage uses Lightning Chakra to speed up his reaction time by making his nervous system respond faster and his brain process information faster. On top of simply being very fast movement-wise, he REACTS very quickly. He also does not use the Raikiri/Chidori. He just shrouds himself in Lightning Chakra and uses hand-to-hand combat maneuvers. A Chidori and a Lariat have the same basic principle, it utilises Lightening nature chakra to concentrate it on the hand, with minimum shape transformation. This is seen as the electric discharge on the hand, which is then used to stab the opponent. Chidori users don’t need to worry about this as long as they have Sharingan, and their body doesn’t need to be unnaturally fast, just fast enough to make it effective.