S0E8: OO Magic Episode 7: The Magic of Being Able to Speak Extremely Fast and Without Hestitation

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.