Proxies

Proxies, also called Shadows, are spirits related to Sprites that resemble sentient beings, generally taking the form of a human. They are parasitic, meaning that they attach to a host for sustenance. They often attach to humans, through a process known as a contract, where the host signs a waver in their blood saying they will provide life force to feed the proxy in exchange for magic abilities; a host can have multiple proxies at any given time. They are also selectively invisible, meaning they can hide themselves to everyone except for those they choose to show themselves to.

Mana
The proxies are capable of providing magic to anyone, whether they reside within the magic or non-magic realm. In order to generate magic, they have to use a resource called Mana, the host's life force converted into a resource usable by others. Thus, whenever one uses magic, their life force depletes; and once their life force is used up, they die. Life force recovers naturally over time.

Abilities
Proxies are capable of producing magical abilities, which can vary by element, rank and whether or not they're passive (used unconsciously or involuntarily) or active (used voluntarily).

Known proxies in the canon

 * Amun
 * Markus Flynn's proxies
 * Horus, primary proxy
 * Sekhmet, secondary proxy
 * Osiris, his Tsinko proxy
 * Isis, Camille Seir's proxy
 * Thoth, Tabitha Seir's proxy