Black Clover‘s strength as a series is intrinsically tied to the appeal of its main character, Asta. Asta starts the series as a magic-less boy, a pariah in his world, before getting the strongest magic in the series. His Anti-Magic operates similarly to magic itself, except ends up much stronger. He can negate any magic, spells, or attacks thrown his way simply by touching them, creating one of the most broken powers in anime.

https://screenrant.com/black-clover-asta-anti-magic-explained/