Kirin is a powerful lightning-based jutsu sasuke only used twice in its entirety naruto series: once against Itachi, and once during the final battle with Naruto. People often assume that he only used it twice because of the complicated setup (requiring to create actual storm clouds in the sky), but there’s actually a hidden meaning behind this jutsu and its level of intensity. Its rarity that true Naruto fans cannot ignore.
When Sasuke finally faced his brother Itachi, he was ready for the real fight of his life. Sasuke’s entire existence was spent avenging his (supposedly) treacherous brother, and he was as prepared as he could be. Not only did Sasuke learn Orochimaru’s techniques for three years, but he also absorbed the old Sannin’s body into his own. However, even that wasn’t enough to defeat Itachi. At the height of the fight, Sasuke, nearly exhausted of his chakra, unleashed Kirin, the most powerful lightning-based jutsu. This involves using fire techniques to create actual storm clouds, then expending only a little chakra to attract a massive lightning bolt, shaped like the mythical Kirin god, to attack his enemies.
Sasuke only uses Kirin against the most important people in his life
Despite looking cool and powerful, Kirin is actually only used by Sasuke twice in the entire series. Mentioning religion and mythology is nothing new to Naruto’s techniques, but Kirin actually has deeper, more layered meanings to Sasuke. First, he uses it against the two most important people in his life (this happened, of course, before Sasuke married Sakura and had a daughter, Sumire). Itachi’s importance to Sasuke is obvious, but the fact that he later only used Kirin against Naruto simply affirms the huge role his opponent/friend plays in life. by Uchiha.
Second, and more interestingly, the Unicorn is a mythical creature in Japanese folklore (actually derived from the Chinese Quilin), resembling a deer with dragon-like scales covering its body. There is nothing strange here, as most of the techniques of the Uchiha are rooted in Japanese mythology. However, Kirin are considered extremely peaceful and enlightened beings. A Kirin never eats the flesh of other creatures and takes great care to never step on any living thing, including insects. When it walks, it does so without trampling a blade of grass. Most importantly: unicorns appear only in times of world peace. They were seen only in lands owned by wise and benevolent people and during the reigns of noble and enlightened rulers, where they heralded a golden age.
Kirin represents Sasuke’s journey in Naruto
So a Kirin represents peace under enlightened rulers, which is basically what happens in Naruto’s epilogue. After a fierce battle, Sasuke accepted the title of Hokage to Naruto, trusting that he would be able to maintain the peace. Undoubtedly, the shinobi world transitioned to a period of relative peace, thanks to Naruto’s efforts to rally the Hidden Villages, who are currently led by the peaceful Kage. Thus, Kirin represents Sasuke’s journey from a life filled with violence and revenge to a life of peace, which would not have been possible without Itachi’s sacrifice and sasuke‘s relationship with naruto.