I got a few questions cause I'm really confused here and there.

1. Can someone give me a quick plot summary? I understand what's going on a few times but sometimes I don't get it at all.
-I'm at the part where I have to travel all the way to Archades after that Kilthias died.

2. What exactly does nethicite do?

3. What's the difference between nethicite and magicite? And the difference between natural and manufactured nethicite (aside from one being man-made)?

4. Are the shards (i.e. Dusk, Dawn) nethicite as well?

5. What do they plan to do with the Sword of Kings (I know it destroys nethicite)?