Guild Wars 2

Does anyone know how to get the Arcing weapon type? Originally I wanted to get a Mystic Shard for my elementalist, because as I understood it Mystic weapons were blue versions of Inquest weapons, but someone recently linked the dagger specifically and it was also red, so identical.

I found out about the Arcing weapons while browsing item databases and so now I’m glad I can get back on track for that weapon model, but I have no idea where to get one. Can someone help me out maybe?

Curiosity compels me to bump.