Demon-Destroyer Sword

The Demon-Destroyer Sword (滅魔の剣) is an ancient Anti Magic Weapon. The sword is found within the central room of the Gravito Rock Zone's floating dungeon.

Description
The sword is summoned out of an opened grimoire, inside which it is stored in the form of writing. The user can easily summon the sword at will without consuming any magical power.

Unlike the Demon-Slayer and Demon-Dweller Swords, this sword has a unique blade end with a wide edge that appears to have a clover symbol at the top. When first seen, it is mostly covered in dirt until Licht picks it up and the dirt falls off to reveal a shiny blade. After it is absorbed into Asta's grimoire, it returns to its dirt-encrusted form.

Causality Break
As well as cutting through magic and spells with its edges, the sword has a special ability, Causality Break (因果解放): It absorbs and removes the effects of spells by severing the cause-and-effect relationship. The sword emanates tendrils of Anti Magic that touch those affected by magic and then draw back into the sword, turning the blade black. Since the ability affects causality, these tendrils negate not only the magic but also its effects, such as the tissue damage caused by a magical poison; the other Anti Magic Weapons are unable to do this and affect only active magic. This ability is even strong enough to negate Reincarnation Magic.

When the sword is wielded by Asta and Liebe's Unite form, a circle forms in the cross-guard, and its magic-neutralizing ability is amplified.

Trivia

 * In Tales of the Rays, the Demon-Destroyer Sword is an item that can unlock the use of the Demon-Slayer and Demon-Dweller: Rotation (断魔&宿魔・旋圏) strike arte.