白刃 はくじん一閃 いっせんじゃなかったです
hakujin'issenjanakattadesu

Noun
Desu Copula

The polite, past negative form of 白刃一閃

1. Wasn't a flash of white blades.; Wasn't a single flash of a white blade.

Past/Perfective
Negative
Polite
Casual Register