Little jester really came a long way, but... since the beginning Luce has shown to have amazing grit, even when she was at the peak of her inexperience and nervousness she really was able to act, showing that what is on the surface doesn't reflect the underlying potential.
And I love that even if Elma does have an incredible finisher... he can't just spam it like there's no tomorrow, it is FINISHER, something he can only use with preparation and calm.
Luce is the damage dealer, and something of a debuffer too, he keeps her safe and she gives him chances to use his finisher if needed.
The story has kept this equilibrium really well.