As one of Shonen's "Big Three," Naruto is one of the most popular anime series of all time. Naruto started off as a knuckleheaded ninja, but by the end of the series, he achieves his dream of becoming the Hokage, and in doing so, he becomes one of the strongest ninja in history. He was the Jinchuriki of the Nine-Tailed Fox, and like other Jinchiriki, he was able to use his Tailed Beast's chakra. Over the course of the series, Naruto uses more and more of the fox's chakra, which gives him access to various forms. These forms are all strong, but Baryon Mode is by far Naruto's strongest form.
Naruto has only used Baryon Mode once, and it happened in the Boruto sequel series when he needed to save the world from a global threat. Baryon Mode gave Naruto a final moment to shine before passing the fate of the Ninja World onto his son and the next generation. It gave Naruto a power that had not been seen in the franchise before, and for a short time, he was the strongest being on Earth. Like many powers of this scale, Naruto had to pay a price in order to use it.
Naruto's Jinchuriki Transformations
Naruto first used the Nine-Tails' chakra when he and Sasuke fought Haku, and he tapped into it again when he fought Orochimaru, Neji, and Gaara during various stages of the Chunin Exams. He later used the Demon Fox Cloak to produce a single tail during his first battle with Sasuke at Final Valley. In these instances, Naruto was still in control of his body, but he would lose more of his consciousness with each additional tail that formed. Whenever the fourth tail manifested, Naruto's body would violently change into a miniature fox-like creature, and he was unable to differentiate between his enemies and allies. His Six-Tails form was the same way, but he also gained skeletal features. These forms were especially dangerous because the transformations would peel Naruto's skin and reduce his natural lifespan.
Naruto needed to find a way to control the Nine-Tails' chakra, which is why he was sent to the Island Turtle in the Land of Lightning. There he met Killer B—the Jinchuriki of the Eight-Tails—who brought him to the Falls of Truth and the ancient temple which allowed Jinchuriki to control their Tailed Beasts. It was there that Naruto fought the Nine-Tails for control of his body, and Naruto proved victorious. From that moment on, Naruto was able to use Nine-Tails Chakra Mode. When Naruto decided to join the Fourth Great Ninja War, he told the fox that he would get rid of the hatred in his heart. The fox saw how sincere Naruto was, and that kindness caused the Nine-Tails' heart to open up. When Naruto was forced to face six reanimated Jinchuriki and their fully released Tailed Beasts, the Nine-Tails agreed to fight alongside him. The Tailed Beast gave Naruto his real name and Naruto released the seal, and in doing so, he became a Perfect Jinchuriki.
Now that he and Kurama were partners, Naruto could use Tailed Beast Mode to fight other Tailed Beasts. This mode allowed him to fight Sasuke in their climactic battle, and it was a huge help during the Momoshiki fight in Boruto. Naruto's Jinchuriki transformations varied in terms of appearance and overall ability, but it is clear that he was only able to use the most powerful forms after he and Kurama developed a true bond.
Baryon Mode In Action
As of now, Isshiki Otsutsuki is the strongest opponent that Naruto has ever faced, and this god-like being was able to overpower prime Naruto and Sasuke as if they were genin-level ninja. While fighting in another dimension, Naruto was stabbed with several black rods that disrupted his chakra, and he was trapped between two large cubes that were created by Isshiki's ocular jutsu. Kurama wanted to protect Naruto's family and the Earth from Isshiki, and he knew that there was only one way for them to win. This is when he told Naruto about Baryon Mode. Kurama mentioned that they would die if they used it, but Naruto agreed to use it without hesitation.
When Baryon Mode is active, Naruto's hair gets spikier, and it creates tufts on each side of his head that look like fox ears. His whiskers get thicker, and the pigments of his eyes grow and curve until they resemble Kurama's eyes. The most striking part of this form is Naruto's cape, which is now comprised of nine red chakra tails. Baryon Mode produces an insane amount of energy, and it significantly enhances Naruto's physical abilities to the point that he can effortlessly counter and parry all of Isshiki's attacks. For example, Naruto was now able to grab Isshiki's black rods with his bare hands, despite the fact they were moving so fast that even Sasuke's eyes could not track them. Naruto is also able to land incredibly powerful punches and kicks that can bypass Isshiki's superhuman durability.
During the fight, Kurama explains that Baryon Mode drains an opponent of their lifespan whenever Naruto makes physical contact with them. This happens because all chakra is connected. Once their chakra makes contact with Isshiki's chakra, his body suffers similar side effects in terms of lifespan. At the start of the fight, Isshiki had over twenty hours of life left, but thanks to Naruto's attacks, he was left with only a few minutes. As a result, Isshiki did not have enough time to implant his Karma into the real Kawaki. This caused Isshiki's true death because he no longer had a vessel for reincarnation.
Baryon Mode's True Cost
Baryon Mode consumes Naruto and Kurama's chakra-like raw materials in order to create a new type of energy. This process is similar to nuclear fusion, which is why it is extremely dangerous to use. It cannot be used for a prolonged period of time, and Naruto cannot make any unnecessary movements because every attack consumes their chakra and respective lifespans. Baryon Mode is in fact a double-edged sword, and if it is overused, Kurama's life will be put in extreme danger. Unfortunately, Naruto did go past the limit, and Kurama's chakra and lifespan were fully consumed. Kurama knew that this would happen, but he did not tell Naruto because he knew Naruto would have never used Baryon Mode if it meant the Tailed Beast was going to be the only one who died.
Kurama's entire being was destroyed, and as a result, Naruto lost access to all of his chakra. He also lost all of his Jinchuriki abilities. Naruto is still a strong ninja who is capable of using Sage Mode, but he lost most of his power when Kurama died. This is significant because Naruto can no longer deal with another Otsutsuki-level threat effectively. It also means that the Leaf Village has lost one of its greatest military assets. Kurama was more than a weapon or a source of chakra, he was a sentient being who came to love Naruto and his family. The two had been together since Naruto's birth, and they were able to become close after the war. Naruto was extremely emotional when Kurama disappeared, not because he lost power, but because he lost a close friend.
Baryon Mode is Naruto's strongest form, but he was only able to use it because Kurama was willing to put his life on the line, and he chose to do so because he and Naruto were very close. This form gave Naruto so much power that he was able to overwhelm an Otsutsuki of unparalleled strength for a brief period of time. Unfortunately, that immense power came at a price. Some Jinchuriki would be fine with the cost, but Naruto is not the kind of person who would sacrifice a friend for a temporary power boost. That being said, Baryon Mode was a very useful power for Naruto to have in his back pocket, especially since no one really knows how many more Otsutsuki-level threats are still around.
