Cosmic Forces Trio

The Rule of Three, among its many uses, was applied to life cycle, given Anthropomorphic Personifications, and both at once.

According to the Greek mythology, the fate of mortals is represented by a woven tapestry created by the three Moirai (Parcae in Roman version). Clotho would determine when someone is born by spinning a length of thread on a spinning wheel, Lachesis would allot the length of time a person had to live by measuring the thread, and Atropos would sever the thread with a pair of shears when it was time for them to die. Straightforward, yet elegant variation.

The Trimurti is the ancient Hindu concept of a trinity formed by the gods Brahma, Vishnu and Shiva. In some versions of the theology (unsurprisingly given its age, Hinduism collected many interpretations and reformations) they represent the concepts of Creation, Preservation and Destruction (or Transformation).

There is no true parallel with Trinity of Christianity which is very accepted in Hinduism today. However, that doesn't mean the concept hasn't fascinated writers and media creators alike. The resulting symbolism and mythology that has come to be associated with each piece of the concept has been combined and expanded by Westerners, in some ways away from the original Hindu gods which used to represent them. If often misinterpreted in various ways. While not as common as some forms of the Power Trio, the Trimurti variations nonetheless crop up on occasion and can draw powerful parallels between characters.

The Creator
The active creative force of the Trio. A character who represents The Creator may manifest in the following ways:
 * The Character may be directly linked through literary allusion to the Hindu god Brahma. Brahma is self-born from a lotus which grows out of Vishnu's navel as he begins to think upon creation. With his eyes open he creates the world, when he closes them to sleep the world is consumed by fire, and when he reopens them again the world is recreated. The Creator aspect is associated with the element Earth (or sometimes wind), the emotions of Passion or Desire, the Spiritual plane and the Soul, and it's heavenly body is the Sky.
 * The Character is associated with some other God or figure associated with creation, such as various Trickster-Creater gods in native American mythology, or the God Abrahamic religions.
 * The Character may have a miraculous or unusual birth, either through the way they were born, who they where born to, or events that took place at the time of their birth. Often resulting in them being The Messiah Archetype.
 * The Character is associated with birth and children in some other way, possibly by having a child themselves, being very young, or having child-like qualities.
 * The Character is known for having created something notable or important, or trying to do so.

The Preserver
The active caring aspect of the Trio. A character who represents The Preserver may manifest in the following ways:
 * The Character may be directly linked through literary allusion to the Hindu god Vishnu or his Avatars. He is considered in many sects of Hinduism to be the Supreme god who supports, sustains and governs the Universe and originates and develops all elements within. Vishnu incarnates periodically for the protection of righteousness and the destruction of evil, and he is most famously identified with his avatars, especially Krishna and Rama which are famously blue-skinned. The Preserver aspect is associated with the element Water, the quality of mercy, the Mental plane and the Intellect, and it's heavenly body is the Sun.
 * The Character is associated with some other God or figure associated with preservation, sovereignty, mercy or healing.
 * The Character may be a healer, doctor or confidant of some kind, or otherwise perform those deeds.
 * The Character is associated with justice, mercy, protection, sovereignty, intelligence, mental faculties, and diplomacy.
 * The Character known for renewing or rebuilding something or otherwise providing reparations or diplomacy.

The Destroyer
The active destructive force of the Trio. A character who represents The Destroyer may manifest in the following ways:
 * The Character may be directly linked through literary allusion to the Hindu god Shiva. Often viewed in a more abstract light, merging the ideas of Destruction and Creation into a transformation. His most relevant aspect to this trope is as Shiva Nataraja, "Lord Of The Dance", the dance being that which brings about the destruction of the world. Or making sure destruction works in the "proper" way rather than meaninglessly (look up why Shiva has blue throat).
 * The Character is associated with some other God or figure associated with Destruction or Death or Revenge.
 * The Character may be a dancer, or warrior, or judge of some kind.
 * The Character may be a associated with judgement, revenge and anger which leads him or her to kill or destroy, or seek transformation and change (for the worse).
 * The Character is known for Killing or Destroying something or someone or otherwise trying to do so.

Some aspects of this trope which are somewhat unique compared to other ensemble tropes, the characters can be more loosely associated than in most other ensembles, meaning they don't have to be in the same group, and are often on different sides of a conflict, representing the opposing forces. But there does have to be a common link between them, one can't simply choose three random character from a series who happen to fit the types. Usually what the characters are the Creator, Preserver and Destroyer of is the same thing.

Also, these aspects are cyclical, and in practice both the Creator and Destroyer will be associated with destroying something, since to create something new, something else must be destroyed and visa-versa, once you destroy something, something new will take it's place. The Destroyer is often associated with evil or something else undesirable while The Creator is represented positively. In other stories they simply take turns - the Destroyer's role is to "clear the place" for a new creation, like a storm bringing down some trees allows the younger plants grow without their shadow.

Compare a similar Greek Ensemble, The Hecate Sisters, and The Three Faces of Eve. This trope is a subtrope of the Power Trio.

Anime and Manga

 * From Naruto, Naruto represents The Creator (miraculous events of his birth, being a messiah figure, childish qualities), Sakura represents The Preserver (A Healer, intelligence and a taskmaster) and Sasuke represents The Destroyer (wants to destroy his whole village, fire and lightning are his chakra elements).

Literature

 * From The Chronicles of the Kencyrath, The three surviving Knorths are very obviously alluded to following this trope in-universe, Torisen is The Creator (Restored The High Kingship), Kindrie (A Healer) Jamethiel "Jame" is the Destroyer (She does a Dance Of Death).
 * From Wheel of Time Three incarnations of The Dragon Reborn may be alluding to this trope in-universe. Rand explicitly calls a vision of a future incarnation of him The Destroyer, and fans has suspected that Lews Theron and Rand represent the other aspects, though which one is debated. Considering Rand healed the Taint in the One Power, it argues for him being the preserver and Lews Theron by default being the Creator, especially since his actions brought about Rands version of the world.

Tabletop Games

 * Werewolf: The Apocalypse mythology has three greatest spiritual entities, imaginatively named "the Triat" - Wyld (supposed to create Chaos), Weaver (supposed to structure the creations of the Wyld) and Wyrm (supposed to squash things when their time has come). Werevolves believe that everything wrong with the world happened because the Weaver went mad (or too frustrated) and began to trap and constrain Wyrm, until the latter also went mad and started burn-maim-kill anything, rather than what it must, and corrupt. There are also individual spirits serving either of the three.

Western Animation

 * From Avatar: The Last Airbender, Aang is The Creator (The Messiah figure who saves the world), Zuko is The Preserver (Becomes Fire Lord and helps rebuild the world after his Fathers wars) and Ozai is the Destroyer (The guy who was going to destroy the entire Earth Kingdom with fire). It shows the cyclical nature of the trope by being The Destroyer-The Creator-The Preserver, chronologically.