Kuro Nero

Born as Secre Swallowtail, she once served as a close attendant to the first Wizard King five centuries ago. To seal away a demon that had crossed into the mortal realm, she invoked forbidden magic — a decision that cursed her into the form of an anti-magic bird known as Nero. For five hundred years, she silently watched over a dormant grimoire, bound by both duty and curse. Her encounter with Asta reignited her sense of purpose, and she has remained steadfastly by his side ever since. After the truth of her identity was unveiled during the Elf arc, she reclaimed her human form and officially joined the Black Bulls.