More basic info on the setting. Since Frenzy is a shaman, that magical tradition and the spirits that are tied to it will be prominent in the role she plays, even if that role may not be obvious to her or the reader in the beginning. More details on Frenzy specifically will be in later posts, as will more specific info on shamans and their interactions with the spirits.
Shamanism as a magical tradition in the F&B universe is instinct and emotion. Shamanism, as a natural ability cannot be trained, it is a conjunction of genetics, state of mind, personality, situation and willingness to cooperate with the spirits. A person can be pre-disposed to the shamanic gifts and abilities, but never experience a situation that will fully awaken them, such as a near or actual death experience (one of the traditional means of awakening and sometimes ritual rather than literally enacted), followed by guidance in nurturing any resulting awareness of the spirits and the potential of self. Many go mad or believe themselves insane when they start seeing spirits and hearing voices after such a life changing experience.
The predisposition to shamanism can be sensed in the astral plane, but it is difficult, and is usually not prompted until the personality of the person indicates a possibility for full awakening. Unlike the thaumaturgist, shamans thrive on chaos and creativity. This makes their spells more variable than a hermetic formula, allowing casting on-the-fly and with personal touches, but it also means they can conjure up much more dramatic and flashy results. Because of this, most shamans are very down-to-earth and free thinking (contrasted to the rigid discipline and thought needed to wield formulated hermetic magic), but the bad ones can be very aggressive, destructive and greedy. All shamans also tend to be good at communication, if not empathy, even if they may not be good with people, this includes artists, singers, politicians, etc. and explains the traditional storytelling role of the shaman as not only a lore keeper, but also a counselor, life guide and advisor.
Spirits are natives of the astral plane, semi-sentient collections of nether that are given power, awareness and direction by the dreams, ideals, beliefs and wishes of the living, but they can also be empowered by the god-like greater spirits dwelling in the astral plane, who were originally brought to sentience by the dreams and influence of the living in ages past. This is how the cycle started, as the thoughts of animals began to influence the nether energies within the astral plane, the equivalent to animal spirits came to be, and as these grew in power, they became smarter and were eventually able to reach across the planes and guide the living animals in the mortal realm. As man gained prominence in the world, the spirits also guided him, giving rise to the system and belief in totem animals, but the higher intelligence of man and his (eventually) high population began to greatly influence the astral plane and the spirits there, making them stronger and smarter still. The relationship between the mortal world and the spirits of the astral plane is key to the power and role of the shaman (more on that later).
Once man started to revere the greater spirits as god-like beings, the nether of the astral plane was drawn to the focus of those thoughts, dreams, prayers and beliefs, building the greater spirits into evermore powerful beings akin to gods. Eventually, the influence of man on the astral plane encouraged the empowerment of human inspired spirits alongside the continued growth of the older, animal oriented spirits. These new spirits would eventually become the angels, devils, demons, succubus, and other powerful and morally aligned spirits. Older spirits were neutral and sought the growth and health of the spirit and mortal worlds, but fueled by the fears, fantasies and religious fervor of the ever creative, human mind, these new spirits embodied not only the depths of malicious depravity and the heights of moralistic purity, but all the grey areas in between which drive the human psyche to ever widening venues of exploration, discover and potential destruction.
The influence of man’s beliefs on the astral plane also means that spirts and the astral plane are very much alive in the areas around cities and modern technology. Television fuels the imagination of humans and that imagination imprints on astral space, awakening the nether with new entities from urban legends, strengthening and evolving existing spirits with modern twists and transforming the landscape of the astral plane into fanciful mirrors of the living world. When the lull in magic came, it severed much of this power increase and cut the spirits off from the world. They retained much of their power, but were unable to grow or cultivate the power.