Episode 21, " Capital Riot ," is widely regarded by fans and reviewers as the moment Black Clover truly finds its footing, shifting from character introductions to high-stakes action.
Reviewers at Anime News Network and Reddit praised Fuegoleon and Leopold Vermillion. Unlike the haughty Silva family, the Vermillions’ willingness to recognize Asta’s merit—culminating in Leopold declaring Asta his rival—was a highlight. Black Clover (TV) (Dub) Episode 21
Even in a serious episode, the "Petite Clover" segment—specifically Mimosa's "best girl" moment—remained a fan-favorite for adding much-needed levity. Episode 21, " Capital Riot ," is widely