Chidori

Chidori (千鳥, "Thousand Birds") — an offensive A-rank Lightning-natured ninjutsu created by Hatake Kakashi. The user concentrates lightning chakra in their palm, and with the chirping of a thousand birds, it transforms into a blade of pure electricity.

Usage: the technique strikes in a swift dash — the user pierces the opponent with their hand at tremendous speed, penetrating almost any defense. Because of this speed, Chidori has a flaw, "tunnel vision": the ninja rushing forward is vulnerable to a counterattack, which is why Kakashi created the technique to be paired with the Sharingan, whose sight compensates for the blind spot.

Legacy: having pushed the technique to its limit, Kakashi once split a lightning bolt with it — for which it earned the name Raikiri, "Lightning Cutter." Later, he passed Chidori to his student Sasuke Uchiha, for whom it became a signature move alongside Naruto's Rasengan.