OO Magic Episode 7: The Magic of Being Able to Speak Extremely Fast and Without Hestitation

Frieren: Beyond Journey's End – Season 0

Frieren and Heiter try the spell out on the taciturn Eisen. At first the spell doesn't seem to have worked, but when they ask him about a recent battle, both his speech and his movements increase in speed. Frieren and Heiter conclude that it's good for people to have their own manner of speech.