Fae are allergic to iron. Some more than others. Iron drains them of their magic and then their life-force.
The mortal realm reeks of iron. Only the most desperate fae still reside in the mortal realm.
Some fae, such as the Court monarchs and the Assassin are immune to iron.
*Thank you for reading. I hope you've found this informative. Don't hesitate to comment and vote. For more, go to my blog Ronel the Mythmaker to learn all you can about these fascinating creatures.*