Abstract Existence

Summary
Abstract Existence is a term referring to a character who embodies a fundamental concept in a physical or immaterial state of existence and will always remain as long as said concept or ideal they encompass continues to exist in some form

Note being an Abstract Being doesn't always qualify as Abstract Existence as the two terms are similar but different

Possible Uses

 * Omnipresence/Nigh Omniscience: Abstract entities might exist everywhere that their concept or theme resides, allowing them to be in multiple places at once.
 * Non-Corporeal: Due to embodying a concept or theme, many abstract beings lack true physical forms, and are thus difficult to physically damage.
 * Conceptual Manipulation: Abstract Entities might have incredible command over the theme or concept that their embody, as it is a part of their essence.
 * Reliant Immortality: Due to being the embodiment of a concept or theme, an abstract entity will exist for as long as its concept does.

Limitations

 * Due to a particular concept forming an abstract entity's entire being, foes who are able to override their command over, and erase it, can destroy them permanently.
 * Abstract entities recurrently strictly embody a concept up to a certain level of reality. For example, Eternity only embodies time on a local, universal scale. If the universe is destroyed, so is he.

Users

 * The Endless (DC Comics)
 * Gaea and Tartarus (Percy Jackson)
 * Death, Eternity, Infinity, and many others (Marvel Comics)
 * Seven Great Demon Lords (Digimon)