Kester Blackthorne
Importance:
A former Ederian Watch soldier, dishonourably dismissed after he maimed a child out of the undercity - and, as Xanthe eventually tells the others aboard ship, one who did it while serving under her command. Karth recognises him when the party finds him with two wolves for company, and escorts him to a cell. He spends the imprisonment working on Karth: how selfish the heirs are, how little they think of anyone beneath them. It lands. Xanthe gets to him first, and they talk around the only question that matters, which is who holds his leash now.
Since then
You are all so certain you are the good ones. So was I, right up until the order came and I went and followed it.