Gaians are nature spirits, whose powers are tied to Earth in the same way that those of Celestials are tied to Aether. Of course, the inherent magic of humans is also tied to Earth; however, while Gaians tend to think of humans as something akin to their children, there are certain key qualities that separate the two:
Given their identity as spirits of place, the personalities of Gaians are defined by the locales they embody. Mariana Trench is cold, mysterious, and occasionally comes out with something really weird. Sahara Desert has a dry sense of humour and an aversion to crowds. Seville is warm, erudite, and easy-going. Unsurprisingly, city Gaians as a whole tend to be more sympathetic to both humans and Celestials than those of less densely populated areas; however, a few exceptions do exist - Swindon, for example, despises humanity.
All Gaians embody one of three elements - earth, water or air. It is generally easy to guess which element a Gaian is aligned with from the nature of its locale, although humans do not always find this entirely intuitive - most modern cities and roads, for example, are aligned with air (rather than earth, as some witches assume).
Gaians don't have much truck with Celestials. Celestials aren't from Earth, so they generally aren't worth associating with. However, Celestial schemes frequently have some impact on our world, especially where humans are involved. Gaians' attitudes towards this kind of activity range from weary tolerance to downright hostility. In reaction to such incursions, it isn't unknown for Gaians to seek retaliation or to preemptively foil Celestial schemes, usually by enlisting the help of humans.
Gaians think of humans as children, to be nurtured. Gaians are often therefore quite positively predisposed towards humans, and are quite willing to work with them. Of course, some humans get in with a bad crowd. Humans who have spent too long around Celestials are seen as misguided children, who may need the help of strong earthly role models to cultivate a sense of their proper heritage. Some humans are seen as bad children. Repeated acts of senseless destruction are unacceptable, and should be crushed… along with the humans responsible.
The act of summoning a Gaian is rather different to that of summoning a Celestial - a major concern when summoning Gaians is to make them feel at home. Gaians can't move freely through Aether as Celestials can, so a Gaian's response to being summoned will either be to send an astral projection of itself (for a sort of metaphysical teleconference in which the Gaian is not physically present), or, if it likes and trusts the summoner, to get on a train….
Being the Gaian of a large city, Greater London is generally friendly towards humans. They take an interest in people from all walks of life, engaging gladly in conversations about all kinds of topics. They are quick to form deep connections with humans, but be aware: their attention is intense, yet fleeting. Associating with them often leads to making your way home via a series of night buses, alone and very confused.
A smooth talking Gaian who's been around for centuries, if not millennia, the City of London only really takes an interest in those humans it considers to be important. Important in this case meaning rich. City springs from London's history of trade, from the deals made in taverns and counting houses, and later in board rooms and the stock exchange. It shows.
Once part of a large network that served Preston's busy docks, Ribble Steam Railway is now just a little heritage line. A modest number of tourists gather each day to watch the line's one remaining engine make its daily journey, closely followed by the Gaian of the Ribble Steam Railway as she runs along the tracks, crying: “Sorry - can't stop now! I'm just… so busy. Always, always… so… busy.”
Yellowstone is… honestly, a bit of a bore. He is keen to point out just how big he is, how he was one of the first Gaians to secure a proper deal with humans, how many dogs he keeps in his back yard. Generally benign, he has a fiery temper when riled.
With close links to the Boggies, Wytham Woods has barely changed in the span of living memory. They are a sweet-tempered Gaian, ever ready to offer passing humans a few freshly-picked blackberries and a story that meanders like a forest path.
A rather cold Gaian who dislikes humans, viewing them as overly uppity penguins. Antarctica feels that it wasn't properly consulted about certain recent incursions into its domain….
Gaian of the deep oceans, Bathya appears utterly alien to humans - indeed, it's never really interacted with humans and doesn't see why they matter. Still, like a rather ugly fish investigating an inviting bioluminescent glow, it has decided to come and see what all the fuss is about.
With a fearsome intellect and a really quite remarkable grin, Nile is one of those Gaians you really wish you knew. But they're just so sophisticated, and you know full well that, if you ever try to begin a conversation with them, you'll start rambling on about how you've always admired reeds, oh, they're just so versatile… while Nile nods patiently, wondering why they never meet anyone interesting these days.
Deeply flattered by all the attention, Ness is nonetheless eager to point out that they aren't hiding any inexplicably hardy mesozoic reptiles under their jumper, whatever the Iron Filings may think. What, this? This is just a… big balloon… that they're… keeping warm under there….