白刃 はくじん一閃 いっせんじゃありませんでした
hakujin'issenjārimasendeshita

Noun
Desu Copula

The polite, past negative form of 白刃一閃

1. It wasn't a single flash of a white blade.; It wasn't just a quick slash.

Past/Perfective
Negative
Polite
Terminal Form