Wishgiver

Wishgivers are mirrors of desire. They are people emptied of self, vessels that are half corruption and half expectation. They hear your thoughts and feelings in their bones - not full mind reading, but a specific kind of need and expectation. If you are missing a distant romantic partner, yearning for the approval of a parent, or hoping for a dashing savior to carry you away, the Wishgiver instinctually hears you and changes their body and mind to accomodate. And the longer they spend attuning to one person (or one place), they better they are at crafting their minds to be undetectable - they can get to a point where, when their target wants them to be innocent of being a spy, they will actually morph to forget their own complicity. 
The full powers and inner experience of a Wishgiver is so far unknown - only a few have been discovered and they are extremely hard to keep captured. They are known to be made from a Lady Zadasa, and so far most seem to originate in Sonev. 
Whether Wishgivers are evil, redeemable, or can be worked with is a subject currently being explored - it is a very difficult question, and one that they are designed to make actively more difficult at every turn.