I usually find copper ore more often than iron, so it would be good for starting when you need armor but don’t want to waste your iron ingots. Plus, a different look (especially with the gradual oxidization effect). Maybe they could make the armor more likely to be struck by lightning, energizing the wearer 95% of the time and doing some damage the remaining 5%. That could also be a good way of creating charged creepers (them lightning bounces from you to any mobs in the near vicinity).
I usually find copper ore more often than iron, so it would be good for starting when you need armor but don’t want to waste your iron ingots. Plus, a different look (especially with the gradual oxidization effect). Maybe they could make the armor more likely to be struck by lightning, energizing the wearer 95% of the time and doing some damage the remaining 5%. That could also be a good way of creating charged creepers (them lightning bounces from you to any mobs in the near vicinity).