"I'm a Stealthy Assassin, and the armor interface I'm wearing lets me refract light around myself, cloaking myself in plain sight. Because really, if you can see my pulsing blue LEDs, you're already dead."
It's actually an old idea of Blizzard's back when Starcraft was young and also around when the Gamecube was around. It's a character named Nova from Starcraft Ghost. A project that just never came to be. :/