Here's a thing that's always very good: the protagonist is getting his ass whipped by the big bad, whips out his new technique that makes him many times stronger which he prepared specifically for this fight...and it makes him just strong enough that the villain goes 'oh, I see, I actually need to fight seriously'.

See: Goku pulling out the Kaoiken on Vegeta

Luffy using Gear Two on Lucci

Kind of the second fight with Vergil in DMC3?

You tried so hard and came so far and at the peak of your power you're just able to force them to actually use some of the bullshit in their arsenal

I AM NOT LEFT HANDED!
I'm not left handed either.