Yukianasa

The Yukianasa (or Yuki) is a weapon with control over ice and snow, the cost? Chakra, and one's free will. The blade was given to Lightning by his sensei, the Yukikage Haruto. The blade absorbs moisture from the air, and uses chakra as a "command" to use this in whatever way the user wishes, if the user is out of chakra but the Yuki is active, then it saps the user's free will.

Quotes:

"The world is unjust, I swear I will be the divine blade of JUSTICE! Yukianasa ACTIVATE!" -Light, activating the powers of the weapon for the first time in real combat.