Why not? Braig wants power. I believe he was the one who originally planned the mutiny of Ansem the Wise.To gain the ultimate weapon, Braig would have done anything, and to have the option become available by an old man who looks like he was about to die would have been the icing on the cake for him.
There is that. My point is WHY does he want all this power? What are his motives? I'm dying to know his reasoning.