But who are they, after all?

Exploration Stage: Room of Fate
From: Valerie
Description: If those wanderers are harmless, maybe they could tell us something interesting? Or perhaps we could exchange something valuable with them... We should really talk to Martha.
Completed: Red Wanderers? I haven't seen them for years; did they really come back? They are products of the Distortion energy and serve as executors of the City's will. The Wanderers appear when particularly powerful artifacts upset the natural balance of power in the City.