Flying Swallow

An addition-line ninjutsu that augments the killing power of a blade — like a kunai or sword — by flowing chakra into it. The materialised chakra is shaped like a blade, cutting up everything it touches. It is also possible to alter the attack range of the weapon by adjusting the amount of chakra put into the blade. Seeing through the movements is said to be very difficult.

The density of the chakra is so high it becomes visible. It not only raises the power of the weapon, but simultaneously turns oneself into a blade as well. The chakra-enhanced blades are strong and sharp enough to cut through solid rock and iron. The technique works best with elemental chakra, especially with wind-natured chakra which greatly increases the offensive cutting power.

Trivia

 * The Flying Swallow is a shōgi piece used in a large-board variant called taikyoku shōgi, which is possibly the most challenging chess-like game in existence, with over 400 pieces of more than 200 types on either side.
 * There may have been a mistake with this techniques classification as the second databook calls it a ninjutsu in its description, but classifies it as a taijutsu.