Luz means "light" in Spanish. Back during the Halo 2-ish 3-ish era, Luz's armor was infected with a rare type of flood that didn't infect him, but made his armor faintly glow in the darkness. Joe liked the idea, so gave him an ability that turns on the glow effect, but can also turn it off. That's why everyone calls him Luz. He also has a rare Active Camo (modified by Joe) which can last much longer then normal active camo. Also, Luz is best with his rare green Energy Sword with a Magnum or SMG. Luz is the ultimate burgler, and could sneak past Smaug possibly better than Bilbo. (Some of you may get that reference)