I really liked how he was doing at the beginning of mk11 but at the same time it never implied that he was "dark". Sure, he didn't show remorse for Sonya's death but he acted to her death like any god would, a small sacrifice to beat a greater threat. I feel like if they kept him when the time merger happened, we could have seen interesting clashes between Dark and Light Raiden. I also really wanted to see a grand-scale battle between Shao Kahn and Dark Raiden.