Bogeyman

Beast Magic: Bogeyman (獣魔法『』) is a Beast Magic spell.

Description
With an open grimoire, the user summons an imp that takes on the appearance of the target's fear. When summoned, the imp appears as a small black creature with smoke streaming from his eyes and back. The smoke then swirls around its body before taking shape. The transformation can draw from and trigger repressed memories of which even the target was unaware.

The resulting terror could be used to rattle the target, causing them to lose focus and leaving them open to attack, or to completely incapacitate the target. Alongside this mental attack, the bogeyman can also physically attack the target because its transformation has solid form.

Trivia

 * A bogeyman is a type of folkloric creature often used to frighten children into behaving.