Rasengan


 * Debut (Anime): Naruto Episode 86
 * Debut (Manga): Chapter 150

The Rasengan is a powerful technique invented by Minato Namikaze, after three years of development it was never completed. Rasengan was meant to be an example of nature manipulation as Minato meant to combine his chakra element with the Rasengan. However, he died before he could accomplish this. Despite this, the Rasengan is still a very useful and difficult jutsu to learn.

Rasengan Training
In Part I, Jiraiya trained Naruto how to use the Rasengan, learning the Rasengan was broken down into three steps. The first step was learning how to burst a water balloon by spinning the water inside in multiple directions at once using only the user's chakra, which emphasizes rotation. The second step was for the user to burst a rubber ball, and since rubber is thicker and air is completely different from water, it forces the user to use denser chakra to break it. This step emphasizes power. The last and final step was to combine both step one and two by spinning chakra inside a balloon without moving the balloon itself, emphasizing stability of the sphere shape.

Description and Effects of Rasengan
The Rasengan doesn't require any hand seals at all, it relies only on the chakra control of the user, and once it's complete, it becomes self-sustaining, which does not give Rasengan a definite limit of use like its counterpart, the Chidori. The chakra spinning at such a speed and compacted into such a small state allows the spinning chakra to grind whatever it comes in contact with, causing major damage to it. When used on a person, it has been seen to grind into them, eventually blasting them back. In addition to this, it can also incapacitate the person it comes in contact with, it can also be speculated that the Rasengan also carries the ability to negate a technique such as Chidori due to the compressed state and the chakra within the shell spinning at high speeds and random directions whereas Chidori is more direct. In an anime filler arc, Naruto was able to perform this jutsu as a mid-range projectile technique by throwing it into a wall. The Rasengan was designed to use the caster elemental affinities, as stated by Kakashi and designed by Minato. Minato was unable to add his affinities to his Rasengan before he died. Kakashi tried to add his lightning element to the Rasengan but was unable to and explains that he uses the Chidori and Lightning Blade instead, which requires a certain point of shape manipulation and nature manipulation itself. Some video games depict Jiraiya being able to add his Fire affinity, but it was not shown in the anime or manga. Naruto was the first to add his Wind affinity to his Rasengan and even advanced it to the point the he was able to create the Wind Release: Rasenshuriken.

Drawback
However, since it requires quite precise chakra control, it can't be used in a place where chakra is continually being drained away or disrupted, like in Jirobo's Earth Release Barrier: Earth Prison Dome of Magnificent Nothingness.

Naruto's Rasengan Usage and Improvement
While the Rasengan is a one-handed technique; in Part I, Naruto has to use two or more hands to use it (although in episode 112, he almost creates a Rasengan with only one hand, but fails due to Jirobo draining his chakra) there was also an incident in episode 99 when Konohamaru had locked himself in the Hokage's study in-order to prevent Tsunade's inauguration, Naruto began to form the Rasengan by releasing and spinning the chakra with one hand while using the other to create the shell however it is unknown whether he could form a fully powered Rasengan or was forming an incomplete version although the latter is most likely true due to Naruto not wanting to risk the chance of injuring Konohamaru with a complete Rasengan's blast by accident, while in the manga version he is using three hands, mostly due to his poor chakra control. He requires the use of his own hand to release and spin the chakra, and a shadow clone's hands to form the shell of the sphere. When he goes into his one-tailed transformation, he was able to make a Rasengan using his hand to spin and the Nine-Tailed Demon Fox's chakra shield to create the shell. Because he mixed it with the demon fox's chakra, the Rasengan had a purplish glow, making it equal in power to Sasuke's Flapping Chidori. The Rasengan can either be handheld or float slightly above the user's hand; Naruto has been shown to hold it both ways on different occasions, although it is now usually the latter.

While in training, Naruto improved the Rasengan with the Great Ball Rasengan, after Jiraiya pointed out during their time away from Konohagakure that it would be easier to hit an opponent with a larger Rasengan. Later, Naruto mixed his Wind natured chakra to start developing the Wind Release: Rasengan as it was originally intended. Naruto took the Rasengan even further than his father by creating the Wind Release: Rasenshuriken, a variant of the Wind Release: Rasengan. However, this new technique also damaged the user's arm and chakra circulatory system, making it a double-edged sword, like Rock Lee's Lotus. Even so, Naruto overcame this obstacle as shown during his fight with Pain when, in Hermit Mode, he threw the Rasenshuriken, preventing damage done to his own body.

Also, a few other variations of the Rasengan have been shown during the fight between Naruto and Pain such as the Hermit's Art: Great Ball Rasengan which is basically two Great Ball Rasengan spheres enhanced by the sage chakra and made in gigantic proportions. He also revealed the Rasenrengan, which are two normal-sized Rasengan spheres, also enhanced by the sage chakra.

Anime/Manga

 * Demon Fox Rasengan
 * Great Ball Rasengan
 * Hermit Technique: Rasenrengan
 * Hermit's Art: Great Ball Rasengan
 * Super Great Ball Rasengan
 * Wind Release: Rasengan
 * Wind Release: Rasenshuriken

Video Games

 * Double Rasengan
 * Fire Release: Great Flaming Rasengan
 * Naruto Uzumaki Rasencombo
 * Rasengan of Truth
 * Sand Rasengan Combo
 * Shadow Clone Rasengan
 * Special Attack Rasengan
 * Three-Tails Rasengan
 * Vermillion Rasengan

Movies

 * Crescent Moon Rasengan
 * Naruto and Shion's Super Chakra Rasengan
 * Seven-Colored Rasengan
 * Twin Rasengan (Demon Fox Rasengan and Gelel Rasengan)