Neverborn Malfeans have almost god-like powers and are potentially the most destructive beings in existence. Thankfully, most of them remained asleep deep in the Labyrinth through most of history, waiting for Oblivion to consume everything; they controlled their Spectres and worshippers through dreams and the powers of the Hive-Mind.
How they came into existence was unknown, and they were thought to have simply been around since the creation of the world. One theory is that they represent the cosmic pain created when life and death were separated. Another is that they represent beings who existed before the universe began or are themselves the shards of dead or husk universes, such as the Qlippoth. The Ascension supplement for Mage: The Ascension states that they are the opposite cosmic force of the Psychopomps, encouraging the destruction of all things as the Psychopomps aim to reunite the One. In The Book of Madness Revised, at least some of the infernal entities served by the Nephandi are revealed to be manifestations or dreams of the slumbering Malfeans.
The Black Hand: A Guide to the Tal'Mahe'Ra suggests the "Children of the Baali" may be the Malfeans. These beings have physical bodies in self-created tombs in the earth, but their souls and minds exist in the Labyrinth, forever dreaming. The Baali seek to keep the Malfeans' consciousnesses from reuniting with their terrestrial bodies through sacrifices and depravity. If this lore were correct, it would suggest, as the Wraith corebook does, that the Malfeans are indeed physical manifestations of the pain of death itself (literally taking on the form of flesh and soul forever severed).
For many wraiths, there was nothing more powerful or more feared until the destruction brought around by the Sixth Great Maelstrom. Only Gorool had been active prior to this, and he was animated by Charon's Shadow, making him something less than Neverborn. It is said that when Xerxes Jones used his nuclear blast in the Labyrinth, the Neverborn began to stir.
Terrifyingly, a force greater than the Neverborn was discovered in Orpheus: the primal being called Grandmother. This plotline is often considered semi-canonical, as the Orpheus metaplot is discrete and frequently contradicts Wraith.
As it was revealed in Orpheus, Grandmother is the "mother" of the Neverborn, making them an ancient and especially powerful type of Sparagmoi. She became determined to devour her own children. She is described variously as the twin of The One and a remnant of a dead universe. For the first time in history, the Neverborn became almost active, attempting to thwart their mother's plans. Although less powerful, the Neverborn had the advantage that they were not blocked by the Tempest like Grandmother, and managed to raise armies by both spawning their own Spectres and "recruiting" from the world above. The helpfulness of their involvement is questionable, however, seeing as they destroy almost as much as they attempt to save.
The game Exalted also presented similar beings known as the Neverborn. These beings are the result of slaying Primordials. Unable to enter the cycle of reincarnation, their great tombs surround the Mouth of the Void.