Rasengan

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

Overview
When performed, Naruto summons a Shadow Clone, and builds up a ball of spinning chakra in his hand. When the special move button is pressed again, Naruto thrusts the chakra ball forward. If the ball hits an opponent, it slowly moves forward, trapping opponents inside and dealing multiple hits, finishing the sequence with a stronger hit that launches opponents. 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. If a directional input is pressed while Naruto is charging Rasengan, he will store the charge and dodge, giving him time to evade enemy attacks and continue charging Rasengan. 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. When fully charged, the move becomes Fūton: Rasenshuriken, although prior to v0.8a, it became Ōdama Rasengan

Origin
The Rasengan is Naruto's signature technique in the Naruto manga and anime. 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.

Trivia

 * If uses this attack after copying it from Naruto, a clone of Kirby 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.