Dark Cloaked Avidya Blunt Strike

Dark Cloaked Avidya Reverse Blade Strike (闇魔法『闇纏・無明峰打ち』) is a Dark Magic spell.

Description
With an open grimoire, the user coats their sword with Dark Magic, dashes behind their target, and strikes the target's nape with the back of their sword. The blow is strong enough to knock the target unconscious, and since it is done with the blunt side of the sword, the target is not grievously injured.