After the Witch Queen uses her blood to remove the limits on Asta's Anti Magic, he learns to channel the energy throughout his body and attains a form where Anti Magic courses through him and covers part of his body. To activate the form, Asta must stand still with one of his swords and concentrate on circulating the energy, which leaves him open to attack.
This form is drawn to strong magic and greatly increases his strength and speed while granting him the ability to fly. This form also clears his mind of all doubts and extraneous thoughts, and improves his focus and clarity of mind. Since the form automatically targets strong magic, Asta does not have to consciously react to an attack, but he also has no control over what it targets and can be led away from his opponent. Additionally, the physical exhaustion of using the form limits Asta's usage to only twice each day, although he can push for a third.
This form does not block all magic cast at Asta.
As Asta begins to coat more of himself in Anti Magically, the overflowing energy swirls around him and erodes magically near him.
Soon after the intense battle against the elves and the devil, Asta has gained better control over his Black Asta form, being able to use a great portion of its power as his own to where he does not fly around out of control.