They are commonly depicted as all-powerful beings who watch over the fictional multiverses and the stories that take place in them, and are not allowed to interact with other characters, though they have done so on several occasions, when the situation demanded it.

This policy of total non-interference came into existence due to a former, well-meant attempt by the Watchers to bestow advanced knowledge on the Prosilicans, who used the nuclear technology gained to create weapons and destroy themselves.

When the Watchers returned to Prosilicus, the survivors blamed them for causing the catastrophe by giving the Prosilicans nuclear technology before they were ready for it.

[12] Uatu is later banished by his race for aiding the Fantastic Four against the threat of his rogue nephew, Aron, the Renegade Watcher, who tries to destroy the universe.

[14] Despite this, the other Watchers have interfered in other civilizations' events, though rarely, notably when the world-ending robot Omegex approached the Milky Way and they deemed it dangerous enough to act directly against it.

There is also a tongue-in-cheek, splintered-off faction of Watchers that call themselves The Critics, who not only observe events, but also give dramatic critique as they take place.

The only known Critic looks similar to other Watchers, but wears a mustache, goatee, dark sunglasses, and, rather than toga, dresses in a tweed sport coat.

Once he realizes that it is from the ancient "First Race", the Unseen is overwhelmed with energy as a one-eyed Uatu is brought back to life.

As the moon's debris start raining down on Earth, the various Earth-based teams and heroes fight off the invasion and attempt to save the planet, while the Fantastic Four journey to space and find Fury, who reveals what's happening.

They could transform their own bodies into light and travel anywhere they wished in the blink of an eye and wherever they went, they soon began to be called the Luminous by the other species.

In truth, the Prosilicans had actually used the technology provided by the Luminous to wage war against every other civilization that existed at that times, leading to a final conflict that wiped out nine-tenths of the universe after an ultimate weapon was used.

Due to the toxic fallout released by the weapon, the Luminous set up a barrier to prevent it from devastating what remained of the universe.