Wind Release: Vacuum Blade

The user exhales wind-infused chakra onto a weapon in order to increase its sharpness, range and lethality. For example, the user can infuse a kunai to resemble a makeshift scimitar or infuse shuriken to increase their range and cutting power.

Trivia

 * In the manga, Danzō only used this technique on a kunai, but in the anime he also used it on shuriken to make them widespread lethal fan blades.
 * Though unnamed in the manga and anime, this technique was named in Naruto Shippūden: Ultimate Ninja Impact.
 * In the anime, shortly after Kabuto reveals the reincarnated Madara to the Fourth Division, a Kumo-nin tries to attack him with this technique.