soul shield location question

[Kiosumi]

so i have been trying to find this specific soul shield i need and can't find it i need a piece of the forgotten brightstone soul shield but idk where it drops or what dungeon i need to do to  get it can someone please help me out and tell me what dungeon gives me forgotten brightstone soul shield?? 

[Lordamion]

It drops by 2 pieces from the 4 blue instances. Don´t remember wich one gives each, but you can see it by cheking the rewards in the dugneon lobby.