Doom Steel Refinery

Doom Steel is a metal of pure evil. It drips acid, and pours green smoke for the wicked, and burns the pure. Even the wicked are at risk of suffering its burn if told to refine, or gather the foul metal. The process of aquiring, and refining it is just as incidious. The metal is provided by the council of evil beings that made Eternity, but they demand a heavy price for it. To aquire the foul substance, one must sacrifice to them that which is good. This makes up the majority of activity from the Children of the Eternals death cult. They find targets, good people within Eternity's populace, and take them under the streets of Eternity. They sacrifice the victims to the Eternals, in exchange for raw Doom Steel.
Tens of thousands have fallen to this evil rite. They are suffering still. They recieve the material as a massive ingot in the form of the person, or people that were sacrificed. Once the material is aquired in its raw form, it must be refined, and shaped into the weapons that the cult wields. When reduced to a liquid state, ready to be poured into a cast, the stuff lets off clouds of foul, toxic green smoke. Even a single breath of the smoke seals your fate. Whithin hours, you begin having halucinations of what is to come of the Eternals' grand plan. You see the world around you burn, and the ground beneath your feet crumble. You see the suffering that they bring unto others, and unto you. Then, this suffering takes hold of you as you burn from the inside out. This innitial release of its deadly smoke is what allows it to to drip, and smoke for the wicked.
The forging process is worse. Once the metal has coolde to the point where it can be hammered into an exact shape, each pound releases a scream. Not just any scream, the evil magic that allows the metal to work, pears into the mind of the one who forges it, and finds the scream of something they loved. Be it a loved one, or a pet. The scream of some living thing they loved fills their ear at p pitch, and intensity that it leaves their ears bleeding. The same smoke pours off the weapon, and fills the room at ground level, like a low rolling fog. It burns the smith's legs to the bone. Still, the magic of the metal grips their minds, and forces them to proceed with the project. The screams still fill the smiths head, and the foul mist still burns their legs. 
The suffering continues until the project is complete. The metal finally releases its hold, but the loss of control over one's actions, the burning that costs them their legs, and the screams that burrow into the mind often leave them in a state of madness. The cult has no use for them after that, and they are often sacrificed to the Eternals for more Doom Steel. The cycle continues.