The Firseid Sandbox
After impressing Smithie Warwick with their prowess in killing some powerful faerie creatures, Nester asked Smithie Warwick to craft him some weapons of cold iron — but discovered that tragically warwick cannot because his skill comes from a contract with King Oberon of the Fae, branded into his skin, that would take his own life should he create a weapon that can harm them. The party agreed to try to find a way out of the contract which, Warwick admits, he does not fully understand the meaning of.
In Faerie, the party declined to use their boon to free Warwick of the curse, though they did try to convince Titania (who said it was not in her power).
The Great Phoenix of the Desert suggested that weapons of great power could be forged using reagents collected from powerful beings that would be capable of doing great damage to the swarm creatures, giving the party a fighting chance should they try to drive the creatures from the Prime Material for an Epoch. Smithie is undoubtably the only forgemaster with the skill for such creations.