Zantetsuken

Zantetsuken (ザンテツケン) is an ability which appears in Kingdom Hearts Final Mix, Kingdom Hearts: Chain of Memories, Kingdom Hearts II Final Mix, and Kingdom Hearts Birth by Sleep. It consists of holding the Keyblade tip-backwards, then performing a single powerful slash through the opponent's body so quickly that the cut doesn't appear until after the technique is finished. It is usually a ground combo finisher, and can defeat minor enemies in a single hit. In Kingdom Hearts Final Mix it requires 2 AP to equip, while in Kingdom Hearts II Final Mix it is only available while using Limit Form. In Kingdom Hearts: Chain of Memories, the damage it inflicts is sharply reduced, and instead it is able to break the opponent's card and render it unreloadable.

Kingdom Hearts Final Mix

 * Sora learns "Zantetsuken" after defeating the Kurt Zisa.

Kingdom Hearts: Chain of Memories

 * Sora learns "Zantetsuken" starting at level 22.

Kingdom Hearts Re:Chain of Memories

 * Sora learns "Zantetsuken" starting at level 27.

Kingdom Hearts II Final Mix

 * Limit Form has "Zantetsuken" as a default ability.

Kingdom Hearts Birth by Sleep

 * Terra has Zantetsuken as a Deck Command, obtained by Melding the commands Stopga and Dark Haze or Sonic Rave.

Kingdom Hearts 358/2 Days
While wielding the Oathkeeper, Two Become One, or Dream Sword, the ground combo finisher is a Zantetsuken-like slash.

Etymology
In the Final Fantasy series, "Zantetsuken" (斬鉄剣) is the signature technique of the summon Odin. It typically inflicts Instant Death upon all enemies.

Zantetsuken