system
Given the following post, respond as if you're commenting on Reddit:
human
Why is iron deadly to the fae?
gpt
When the world was young, and all the spirits of the world were more 'awake' than they are now, the Faeries brokered a deal with Iron.  What they asked for, and what Iron was to get in return is lost to history, but it is remembered to this day that the Faeries did not hold up their end of the bargain.

Because of this slight, Iron is *still angry at the Fae*.