Rasengan

Rasengan is 's standard special move in Super Smash Flash 2.

Overview
When performed, Naruto summons a Shadow Clone who builds up a ball of spinning chakra in his hand and then hurls it forward in an energy ball that explodes into a larger projectile if it hits the opponent. Once exploded, the ball moves forward slowly, trapping opponents inside. The move can be charged to deal more damage, and the energy balls have two stages before their fully charged version, with the lesser charged version being weaker and smaller than the other. After the initial hit when Naruto hurls the ball forward, the attack deals a long range of gradual damage to opponents hit; the more it is charged, the more damage it deals. Aside from being fully charged, the attack deals anywhere from 10% to 14% damage to the opponent if all the hits connect, with moderate knockback at the end.

Rasenshuriken
Fūton: Rasenshuriken, or simply Rasenshuriken, is Naruto's fully charged version of Rasengan in Super Smash Flash 2. Instead of hurling the chakra forward as a ball, Naruto instead throws the projectile in the shape of a large shuriken, dealing multiple hits and strong knockback if it hits an opponent. The projectile has a decent range and flies horizontally, exploding after its travel. Much like with the standard Rasengan, opponents hit by the move may be trapped for the move's duration and dealt up to 23% damage, assuming all hits connect. Additionally, if an opponent is close enough to Naruto when he activates the move, they will be paralyzed for a moment and take an additional 3% damage, as well as the full force of the projectile when it gets thrown.

Origin
The Rasengan is Naruto's signature technique in the Naruto manga and anime. It is a powerful A-rank technique invented by the Fourth Hokage, Minato Namikaze, which he created by observing the Tailed Beast Ball. Minato spent three years developing the Rasengan; his plan was to take the shape transformation of one's chakra to the "highest possible point" and then combine it with his chakra's nature affinity, creating a technique that did not need the aid of time-consuming hand seals to control. He died before he could accomplish this, but on shape transformation alone, the Rasengan is still a very useful, powerful, versatile, and difficult technique to learn and master.

The Rasengan does not require any hand seals to use, relying only on the chakra control of the user. In the case of Naruto, he uses a Shadow Clone to help with shaping the chakra into a sphere, similarly to how he does in SSF2. Once it is complete, it becomes self-sustaining, which does not give the Rasengan a definite limit. The compacted nature and moving speed of the chakra allows the Rasengan to grind into whatever it comes in contact with to inflict major damage. This tends to launch the target backward after being hit or, if the target is lying on the ground or being launched to the ground, the destructive force is enough to form a crater. The trapping effect the Rasengan has in SSF2 could be a reference to the Naruto: Clash of Ninja series, where the Rasengan would trap and damage the opponent multiple times in succession.

A special technique invented by Naruto called "Wind Release: Rasengan" can also be performed using his Shadow Clones, where a third clone adds the wind nature to create a more powerful variant of Rasengan. After he figured out the move's principles, Naruto invented the Rasenshuriken, a similar technique he often has the help of three Shadow Clones for, though by the time of The Last: Naruto the Movie, Naruto is able to create Rasenshuriken without aid. Unlike the Wind Release: Rasengan, additional shape transformation is applied to the Rasenshuriken, creating four large points around the central Rasengan core, giving the appearance of a fūma shuriken.

Rasenshuriken require a great deal of chakra to perform: Naruto has been shown creating as many as three Rasenshuriken on his own before tiring out. If he attacks with the Rasenshuriken similarly to how he'd attack with the Rasengan, his arm suffers severe damage, but if he throws the Rasenshuriken, he takes no damage. After travelling a certain distance or colliding with a target that it can't slice through, the central sphere of the Rasenshuriken detonates, producing a vortex of wind in the immediate area. Within this vortex, countless microscopic wind blades are created, which damage anything within the vortex on a cellular level, attacking the chakra circulatory system to such a degree that no amount of medical ninjutsu can heal it. Tsunade likens the damage to poison, and warns that if the damage is great enough, those affected by it won't be able to use jutsu again.

Trivia

 * If uses this attack after copying it from Naruto, a clone of him will appear. However, this clone will not be wearing Naruto's hat.
 * Prior to v0.7 of the SSF2 Demo, the exploded ball of chakra would not move forward at all, instead remaining directly in front of Naruto.
 * Prior to v0.8a, fully charging Rasengan would allow Naruto to use Ōdama Rasengan instead of Rasenshuriken.
 * Prior to v0.9a, Naruto would summon two Shadow Clones to help him charge the Rasenshuriken as it is released.
 * Prior to v0.9b, 's Reflector, 's Proto Shield, and 's PSI Magnet could not weaken, deflect or absorb the Rasenshuriken. However, Mega Man's Proto Shield could absorb some of the knockback, thus allowing him to recover more easily. This was fixed afterwards.