Rasenshurikunai

Shiro Wushazaki created this technique as a combination result of the Rasenshuriken and the Rasenkunai.

The user forms a Rasengan while simultaneously applying two different shape transformations to it, causing it to gain the signature blades of the Rasenshuriken and the signature blade of the Rasenkunai. It has immense cutting and drilling power, which can further be empowered with the addition of different chakra natures. It possess the ability to increase and decrease the size and length of its drill and blades independent of one another at the will of the user. The user can slam this projectile into the target, which will inflict massive damage on them if successful, but will also deal considerable damage to their arm as well. It is also able to be thrown, as Shiro demonstrated. This attack it very dense in nature, several times as dense as a normal Rasenshuriken, and due to this, Shiro has to often

Different Forms
Their are different shape variants employed in its usage by Shiro, each with its own unique effects and drawbacks.

Windmill Shuriken Variant
The windmill shuriken variant has much longer chakra blades than the normal variant does, and its shuriken blades and kunai-drill can be "detached" from the central Rasengan, extending its range greatly, but reducing its duration significantly. This variant consumes less chakra, as it expands differently than the normal form.

Twin Cyclone Variant
While forming the initial Rasengan, the user adds another rasengan that's spinning in the opposite direction on top of the first. This effectively gives the Rasenshirukunai three sets of blades, and one drill. The kunai blades on the bottom near the users hand will move toward upwards and converge on the first drill, fusing the four divided kunai blade drills with the first to increases its size and power. It's called the Twin Cyclone variant because it has two sets of counter rotating blades flowing one on top of the other, giving it twin the cutting power and vacuum suction. It is extremely dense and requires a very strong person to throw it.