"I do, most people go their whole life wondering if gods and the afterlife exists, and I am sitting here having a conversation with the grim reaper, so is it so ridiculous that I believe that karma exists?"
*she laughs lightly* You have a point, I myself am just a anthropomorphic personification of various beliefs of Death after all.
*she thinks for a few moments before speaking again* You believe what you wish, just as many other beings do, as long as it is true to you it is so.
If you want Justice find it and earn it. If you
really think there is some ideal order in the worlds, some righteousness by which the universes may be judged then prove it. But remember, many that live may deserve death, but there are also many that die that deserve life. Do not be too eager to deal out death in judgement, if you don't want to serve the consequences of more pain when you can't bring back those who deserve life.
*with this she gets up from the chair to walk to her desk, flakes of skin and muscle falling to nothing as her death form slowly returns*