All Descendants, including the Guardians themselves, are born without conscious access to their innate abilities, and live through much of their early lives as any other of their species. During this time, a Descendant's powers remain dormant, up until around puberty, when their powers finally surface in what is called a "Manifestation".
The Manifestation "Trigger" Edit
A Manifestation is commonly triggered during puberty, though the exact age varies from individual to individual; on average, the age at which Manifestation occurs is around 12 to 19 years of age, though some Manifestations have been recorded at unusual ages such as 9 and 25.
In species other than humans (such as in Descendant Seraphim), Manifestation generally occurs during that species' version of human puberty. Some exceptions to the timing of Manifestation occurring include that of Libras and Descendant Siphons, who "manifest" their abilities at birth.
While relatively uncommon, a Descendant's abilities may also manifest in times of extreme need or stress. Around 15% of Descendants undergo Manifestations due to extreme emotional and/or physical stress, such as the death of a loved one or physical torture. An even lower percentage undergo Manifestation in times of great need, such as in life-threatening situations to themselves or loved ones.
The Time of Manifestation Edit
Generally speaking, magical/psychic/physical abilities tend to manifest earlier than other ability types at around 12-15 years of age, with cosmic abilities manifesting later (around 16-19 years of age). Elemental abilities do not follow this trend, and instead manifest across a larger range of age. In most known cases, the earlier the ability (or abilities) manifest in a Descendant, the more powerful they are.
For the majority of Descendants, their abilities manifest altogether and uncontrollably at once, though with rigorous training a Descendant may eventually gain full control of their abilities. Many abilities have often been known to change and develop alongside the one who possesses them, and thus the abilities that first manifest in a Descendant are rarely the same abilities they have after a few years.
In extremely rare cases, even before proper Manifestation, a Descendant may show underlying signs of their abilities-to-come; in such cases, the Descendant in question is called a "seedling".
Known seedlings have included the youngster Nicolaj Vortanov, who naturally gave off a strong emotional and physical warmth in those around him that eventually manifested as an intense pyrokinetic ability. Another example include Alexei Gaultier, who as an infant seemed to know the location of his loved ones even when not in their presence that manifested as a powerful global location and revelation ability.
Regardless, these underlying signs often result in said Descendant "seedling" undergoing Manifestation at an extremely early age, and with an unusual innate control of their vast abilities.