The truly incredible battle with Sabi Hakuhei. Highlights include Hakuhei splitting the sea with his sword and dueling Shichika as they flee from the water rushing back in, casually bisecting a shark without turning to face it as it attacks Togame, their clash destroying an island, and Shichika using the fractured mountains as Stepping Stones in the Sky. There's a reason it's referred to as the greatest fight in all of anime. Except not, because it happens completely offscreen.
With no weapons, he manages to destroy 11 legendary swords with minimal effort, and the 12th only required effort because of the skill as his opponent. Proof positive that it isn't the weapon that matters, but the hand that holds it.