"What, Ratchet?" Emily asks. "He's less of a friend... more like a feral spirit who recognises the mutual benefit of working with me. I never made him, he was already here. He sticks around because this place spends all day five ta six days a week with fixing, repairs and creating. The garage fits his resonance - it's not really any more complicated than that. Like a dive bar developing local anger or friendship or whatever." the older Ithaeur shrugs. "You can try and talk to him, but he's a quiet one. Would rather help than say anything."
Okay, tldr , Rathet is an entirely fluff-based spirit. He is not a Merit and gives no advantages whatsoever.