Probably outlining the campaign would help now wouldn't it?
Your family, the Rashaan, has fey blood running through their veins. Unlike most of their type, they did not retreat to the wilderness and hinterlands as civilization advanced, but instead embraced city life. Them and the very few like them are responsible for allowing fey power to stay in the land, even when cobblestones and buildings outnumber the trees and glades. Their presence prevents destruction of the last remaining places sacred to the fey, such as pools, dryad trees, and fairy rings.
In this world, as civilization advanced, magic has retreated, and only the few willing to devote their lives to study could tap it. In game terms this means that while magic is not unknown even to peasents, it's only practiced by a few. Adepts, druids, and clerics far outnumber wizards, but even then you're more likely to see an adept responsible for several villages, or a handful of druids guarding a forest. Clerics are plentiful only in comparison.
You are some of the most powerful spirits left amongst the cities. If the Rashaan are killed, or their blood corrupted, more places sacred to the fey will be plowed under, cut down, or made into wells. And whilst you have great power, you still are only visible to those with a pure heart. Prolifiigate use of magic to manipulate others will bring unwelcome attention, particularly from the Unseen Realms. It is better to help guide and support the Rashaan that try to go willy-nilly all over the city spending magic like water.
And if you want to go with a more recently-born guardian, feel free! Someone is going to have to be an old hat at this, but several others could be more recently arrived to the Rashaan's gardens.
