Famed as the Copy Ninja, Kakashi Hatake is one of the strongest characters in the world of Naruto. Having been introduced as the leader of Team 7, Kakashi went to establish himself as one of the strongest and, at the same time, most influential characters in the entire series.
Being a mentor to the likes of Naruto and Sasuke, he had to live up to high expectations and he did so without fail. Throughout his time as the leader of Team 7 and even as a Kage, Kakashi, time and again, proved his strength. In fact, his genius as a combatant is such that, over the course of years, he came up with countless of his own techniques, and one of the strongest of them ended up becoming his signature technique, called Raikiri.
What Is the Raikiri?
To understand Kakashi's Raikiri, fans need to take a deeper look at his past as a ninja and how he grew stronger over the years. As a child, Kakashi was deemed to be a prodigy. In fact, he is the youngest Chunin and Jonin to exist in the world of Naruto to date, and it was quite apparent that he'd be an excellent ninja in time and perhaps even a Kage one day. At some point, Kakashi was assigned to Minato Namikaze's team and in doing so, he got to learn the trade of ninja from the very best.
Minato, being quite skilled himself, was attempting to perfect the Rasengan by adding nature transformation to it, however, couldn't succeed at this attempt. Kakashi, who was a Jonin by this point already, also learned the Rasengan and could use this technique perfectly. In fact, he even attempted to add his nature transformation to the jutsu. Just like Minato, however, Kakashi ended up failing as well. His failure at creating the Lightning Release: Rasengan or a variant of the jutsu is what ended up giving rise to the Chidori instead.
Over the years, Kakashi went on to master the Chidori to a great extent, especially thanks to the Sharingan that he received from Obito Uchiha before the sad fate that he faced in the battle of Kannabi Bridge. As his control over the Sharingan grew, so did his skill with the Chidori. Kakashi then went on to master the Chidori and make it an S-Ranked Jutsu from an A-Ranked one and, in doing so, made it much stronger.
This stronger version of the Chidori came to be known as the Raikiri. The name Raikiri was famously given to this technique when Kakashi Hatake entered his name into the book of legend by famously splitting a lightning bolt in half with this technique. How much different it truly is from the Chidori isn't known, however, the higher rank implies that, in some way or form, the Raikiri is stronger than the Chidori.
How Strong Kakashi's Raikiri?
Just like Chidori, the Raikiri is a Lightning Release ninjutsu that is performed by gathering large amounts of lightning style chakra in the palm. While chakra can't usually be seen, the Raikiri is so dense that it actually ends up taking a physical form.
This lightning-style technique produces a chirping sound, which is where the alternative name, Chidori, comes from. The technique is then used to stab the target by running towards them at blazing fast speed which is aided by the lightning release chakra. The speed offered by the Raikiri is such that barely anyone is able to react to it and dodge it successfully, however, those who do can counterattack effectively.
Users of the Chidori and the Raikiri, such as Kakashi and Sasuke, carry the risk of being open to a counter-attack, unless they have the power of the Sharingan. With it, they can even notice the most intricate of movements quite easily and then react accordingly, bypassing the problem of tunnel vision. The Raikiri is mostly aimed at the heart of the target and, if it connects, it is powerful enough to kill the target in a single hit. This is precisely what made Kakashi quite a dangerous person to take on in combat.
Although the Rakiri is quite powerful, Kakashi cannot utilize it in combat anymore. This is due to the fact that he lost his Sharingan in the Fourth Great Ninja War. However, this didn't weaken him in combat as he came up with a replacement for it shortly after. Kakashi now relies on another Lighting Release technique called Purple Electricity. This technique works quite similarly to the Raikiri but can be used from a distance, making it much more convenient to use without the Sharingan.