決戦

decisive battle, showdown

k e̞ sː ẽ̞ ɴ
決 decide; settle + 戦 war; battle
noun Rare #38,543
decisive battle, showdown Often used for a major, decisive contest or confrontation, not only a literal battle.
JA: 明日は決戦だ。
EN: Tomorrow is the big showdown.

みんないよいよ決戦だぞ

Everyone, it’s finally time for the showdown!

— 七人の侍 (1954)

いよいよ決戦だぞ

The final showdown is finally here!

— ハウルの動く城 (2004)

いよいよ明日は決戦だな

Tomorrow’s finally the big day.

— 七人の侍 (1954)

Sounds similar to