Yep, it's another Asuran Medium class! This one actually precedes my Engineer by about a year though.
My Thief is actually one of very few characters and armor schemes I will tolerate the Fractal Backpiece on. Of course, "back in the day" I put them on anything and everything once they released the Wardrobe. Now that the "magic" has long since worn off, only a select few themes incorporate this backpiece.
The Fractal Backpiece is certainly overused however with the right colors, and a matching set of weapons, I think it meshes very well with Asuran T3 (Light, Medium, or Heavy).
As a note, I did commit to the look with a total makeover kit to match eye color to the armor glow. The hairstyle accessory color can also be changed to match your armor.
As always, comments welcome and I hope you enjoy the look and find something to take away and make your own!