Huh, I never posted this here.
This is just notes, and subject to being updated at any point.
Steel is normally used for weapons that aren't made from powers because it's easier to forge. Effects Descendants the same way as anyone else.
Lead from the Earth's Core in theory was just for Descendants of Pitch, however when the Descendants of Bunnymund joined and lost the meteor weapon stash they found it easy to get to. After a while they found a way of making it so that it couldn't hurt them. EC lead is toxic to Descendants that are considered 'light' which is most of them, so makes an effective and painful weapon against the Human Order of Guardians. It has a similar effect on 'light' Descendants as Celestial Bronze or Imperial Gold has on demigods as it sucks in their 'light'. However, if the weapon hits anything vital, no matter how lightly, the injury instantly becomes fatal. An attack that allows the metal into the body e.g. stabbing, will cause a temporary lose of powers to anyone who has them. For temperature based powers this can be deadly in itself.
Light enhanced lead is lead from the Earth's Core that has been exposed to constant natural light for a week. This makes it non toxic to 'light' Descendants and painful, but not toxic to 'dark' Descendants. Because of the process used to enhance it, HOG doesn't have much of it.
Meteor metal is difficult to come across, especially since the collection the Descendants of Bunnymund had disappeared off the face of the earth. It is pure white and toxic to 'dark' Descendants. At the moment there is only enough meteor metal for each Head to have one weapon, primarily for ceremonial purposes, but they can be used in combat. They're forged from meteor metal with a small pinch of stardust and then tempered in moonlight.
HOG's supply of stardust is very small, so is used sparingly.
Meteor iron has been used historically by normal people, but the Descendants of Bunnymund found a way of not using the iron, instead using the properties of the meteor and their own powers to make the metal in weapons that can drive away the darkness. Only the Descendants of Bunnymund know the exact method of forging these weapons, much to the annoyance of the Descendants of North.
One of the reasons it's so difficult to get hold off is because buying meteorites is ridiculously expensive.
Descendant classification. (Ones that appear in the story)
Light Descendants: Descendants of the Guardians, Descendants of Mother Nature.
Dark Descendants: Descendants of Pitch, Descendants of Lupine, Descendants of Mortimer (Sadly, death should be neutral but it's often based on public perception)
To determine toxicity, the metal will be painful to the touch of the opposing Descendant and will cause incredible pain if injured with it. Any injury, even something like a paper cut, inflicted by the metal has the chance of becoming fatal, it depends on the severity of the wound how long that will be. The less severe the wound the longer it will take for metal's influence to essential poison the victim.
In victims with actual powers (Not including Descendants of Toothiana etc.) if the wound is severe they will notice a significant drain or even temporary loss of their powers, and in temperature based Descendants they will experience a temporary change in body temperature, leaving them close to hypo/hyperthermia.
Descendants can often sense whether a metal dangerous to them is in the vicinity, and will be struck with a desire to stay away from it at all costs.