Images:

gw2-crystal-guardian-greatswordgw2-crystal-guardian-greatsword-2gw2-crystal-guardian-greatsword-3

Set:

Slot Item Name Trading Post Preview Code
Greatsword  http://db.dulfy.net/item/44985 GW2 TP [&AgG5rwAA]

Where to Obtain:

Champion Boxes: Gilded Strongbox, Branded Strongbox

Particle Effects:

Frosty effect around the blade