Fūton: Rasenshuriken

Fūton: Rasenshuriken, or simply Rasenshuriken, is Naruto's fully charged version of Rasengan in Super Smash Flash 2. It replaced Ōdama Rasengan in v0.8a.

Overview
Instead of hurling the chakra forward as a ball, Naruto instead throws the chakra, now 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 are 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
A special technique invented by Naruto called "Wind Release: Rasengan" can 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 Rasengan's principles, Naruto invented the Rasenshuriken, a similar technique he often has the help of three Shadow Clones for, although by the time of The Last: Naruto the Movie, Naruto is able to create Rasenshuriken without aid. Unlike 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 requires a great deal of chakra to perform, as Naruto has been shown creating as many as three Rasenshuriken on his own before tiring out. If he attempts to use Rasenshuriken similarly to how he uses Rasengan, his arm ends up suffering severe damage. This will not happen if he decides to throw it, instead. After travelling a certain distance or colliding with a target that it cannot 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 damages anything within the vortex at a cellular level, and damaging 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 will not be able to use jutsu again.

Trivia

 * 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, '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.