Add ambience like vasquez said, and also some diffusion too Both are set to 0 in the default galss presets, I reckon. You can also experiment by duping the sword, making the duplicate a hair smaller. It will now appear to have a lighter center. Also you can tweak it by setting the smaller one to be "fuzzy". They wont shed light, nor will they cast shadows, but they'll give the illusion of being made from light.