A clean chekhov-explicit prop-tell: an unexplained on-page effect (a sword thrust becoming a ranged blast) flagged by the cast’s own surprise, seeded on a Zoro swordsman-rivalry beat. Generalizes Oda’s habit of demonstrating a combat phenomenon (a ranged sword strike) as a one-off “how did that happen?” before it is normalized into a named technique. Cross-link Worlds Greatest Swordsman, Shusui Black Blade O Wazamono Named At Thriller Bark.