Considering the Guardian Games theme, I would assume it is probably Rivalry Stoic. Unfortunately, there aren't any all black shaders to my knowledge, but there are a few mixed shaders with good looking black palettes in them: Amethyst Veil, Carminica, Bloody Tooth, Rivalry Blacksand (I think), New Age Black Armory, and Valkyrie Zero to name a few. I myself have often used a mixture of Bloody Tooth, Amethyst Veil, and Carminica.