So your world had some ancients that managed to seal away some sort of powerful being - Good, Evil, Neutral, it doesn't matter. But the thing is, they didn't seal it in a thing. They somehow managed to seal it into a person, who may or may not be aware of it. This is Sealed Power In A Person
A Subtrope of both Sealed Evil in a Can
and Sealed Good in a Can
, this is where the can is a person (Or in some cases, people). This is not where a standard person is what was sealed, unless they were sealed into another person. This may or may not result in the death of the 'can'. Sometimes the sealed being is reduced to a mere mind, and ends up taking over the body of the 'can'.
- Jean Grey was the can for Dark Phoenix in the animated series of X-Men.
- In Dogma, God was sealed in a comatose man on life support. He had to be unsealed by taking the man off life support, thus killing him.
- Naruto - This trope describes the Jinchuriki, people who have tailed demons sealed inside them. They include the title character Naruto, Gaara of the Desert, and Kirabee who contain the Nine-tailed Fox, the Ichibi, and the Eight-tailed Ox respectively.
- Teito Klein, the protagonist of 07-Ghost, is revealed to contain inside himself Pandora's Box, the sealed body of the death god Verloren
- Glory in Buffy the Vampire Slayer. Sealed in Ben, who became a doctor. Eventually Ben was killed in order to kill the unkillable Glory.
- The main premise of Bastard!!!!