The best way to be invisible is to be lowly, scorned, and in servitude. Or at least, appear to be. The thing about whores is that people see them as sex toys who are enslaved to both brutal underworld types and whatever meager cash they can scrounge. And often, this is the case. But to an enterprising mind, access to the most intimate parts of a client's world (pun intended), is a great opportunity. Besides the scruffier customers, sex workers are also called upon by the middle and upper classes, sometimes as paid, live-in retainers. People talk when they don't think anyone important is listening. People let their guard down around people they think they have power over. Imagine the underling is a spy or an assassin.
Elves that still serve Keyldynan in positive ways are few, but their influence can be large if they extend their circles to include half-elves and their friends. Everyone desires half-elves, so it isn't hard to find them a place in a brothel or an elite cadre of courtesans. Given the industrious, passionate nature of half-elves and the deep well of elven secrets, Keyldynan's scarlet recruits are a formidable lot, with access to magic and martial training, as well as stealth and silver tongues. The Gardeners watch politics with a careful eye, supporting here, removing there, giving the more forward-thinking and sympathetic forces in the world a quiet leg up. Many potential heroes have found their paths clear, and many tyrants have died of mysterious causes in the fastness of their strongholds. And all the time Keyldynan's army moves in secret, building a future that can bring hope out of the chaos in mortal society.