The Fomor were a nation of assorted outcasts, with Kemmler’s death those associated with him would have sought sanctuary with other powers. The Fomor are a good candidate. Corpsetaker clearly had an association with them, through Listen.
Nameless, who worked with Kemmler (rather than for like the heirs) sought asylum in Winter, but he appears to have been alone and his motives may have been to undermine Winter. If Nameless isn’t Cowl (as Cowl scorned the Heirs and they scorned him) then his entry into Winter would have ultimately been to spy for the Fomor and the Heirs, that connection alone would have led the Heirs to be welcomed into the ranks of the Fomor. The Heirs however were largely wiped out in Grave Peril except Corpsetaker who met their final curtain in Ghost Story, but Nameless was still around at up to and beyond Battle Ground but had been expelled from Winter Lands following the events of Proven Guilty.
Did Nameless and Corpsetaker work together after Proven Guilty? If Nameless couldn’t provide up to date intel then Corpsetaker had nothing new for the Fomor which is why they were meh about helping Corpsetaker get a new body. Nameless isn’t even inferred in Ghost Story (but neither is Cowl). Nameless would have a tremendous help to Corpsetaker powerful and resident in Chicago in claiming a new body, but apparently not called upon (another reason to think Nameless is Cowl, and his penetration of Winter was for the Black Council and not directly the Fomor).
I have always thought Listen was working for Cowl/Nameless rather than the Fomor, he was a double agent, not bound by Winter Law. In that case he may have been running interference for Cowl/Nameless with Corpsetaker ensuring Corpsetaker wasn’t properly aided by the Fomor. The reason? Nameless is a Demi -god of Discord and is using the Fomor.
