Weapons do this too: see Asmodian Draconic Weapons and Elyos Draconic Weapons.

Its a nice little touch that really drives the point home in the feel of combat in game. When you’re not fighting you look like you’re not fighting, when you do engage in combat you really look and feel battle ready and powered up.

It’s the PvP armor post yay! Here is a look at what the Lv 50 (currently the end cap) PvP armor looks like. You get the armor through earning Abyss points by killing enemy players or by killing lots of Balaur in the Abyss. As I explained in Part 1 of this little series, the really beastly high level armor will look pretty plain when not in combat, but the moment you enter a battle it will flare up and augment. These images are a perfect example: see Asmodian PvP Gear and Elyos PvP Gear.