Elite Black armour is a set that requires 40 defence. The set is currently only obtainable as a rare reward from mystery boxes.

You can obtain mystery boxes by:

Completing certain tasks.
Recieving one as a vote sortition reward.
Purchasing premium point pakages. (Larger donations result in more mystery boxes).
Receiving one as a reward from the Crystal Chest

Elite Black armour has stats similar to rune, so it is basically just a cosmetic set, worn only to show wealth.

Elite Black Armours Stats

Full set of Elite Black Armour

Elite Black Full Helm

Elite Black Platebody

Elite Black Platelegs