Just to compile the evidence for what I’d consider the most likely hypothesis, that being [spoiler]The Toymaker is an artificial creation of the Watchmaker’s Daughter:
[1] He has waxlike hands and never drinks, which along with oily tears demonstrate that the Toymaker is not human.
[2] The art for the Unsettling Toymaker is reused from the "Playing with Broken Toys" storyline associated with the Watchmaker’s Daughter. The puppets created by the Watchmaker’s Daughter are able to act somewhat independently like a prototype of the Toymaker.
[3] In the ghastly ending, the Toymaker’s creation is donated to the Relickers and they want him to take on "another apprenticeship". He says the telling line, "They say my new master knew my old mistress. I have so much to learn!" The Relickers are servants of Mr Cups, who had taken a keen interest in the Watchmaker’s Daughter.
[4] The Toymaker has access to Vesture silk, while Cousins are outright hunted within and outside the kingdoms of the Presbyterate. With his apparent wax characteristics, his ability to obtain this silk if he were a Cousin would be severely diminished.
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