A power only non-superpowered / supernatural Characters can posses.
Formerly Muggle Only Power. Muggles lack powers and abilities, if a muggle should ever acquire one they stop being a muggle. This is one of the reasons being a plain vanilla muggle tends to suck, and Badass Normal notwithstanding, most are relegated to Innocent Bystander. There is one interesting exception though, in the setting there are one or more abilities that only muggles can use or activate. If a muggle ever gains powers or stops being a muggle (say through Super Empowering, cyber/genetic augmentations, or a Viral Transformation) they lose the ability. For one reaosn or other Supernatural beings don't have it so it's extraordinary to them. If they try to gain this ability they'll always fail or end up with at best a weak (or dangerous) copy. The ability might be something perfectly mundane, like creativity/fertility, or quasi-supernatural (the ability to nullify or cancel magic, or a sixth sense). It's usually a "passive" ability, like seeing in color, though if it's a talent muggles have to actively use it (creativity for example would require they paint or compose music). The abilities may be universally held by all muggles or a talent only some possess. The reason a setting might have a Muggle Only Power is to create some form of competitive balance, to have a reason for The Arthur Dent to hang around, or to draw symbolism on the nature and limits of power and mundanity. Contast Virgin Power.
Examples:Anime and Manga