Like Tyron, I view this as cheating. If the developers wanted you to be able to redo rolls, they would give you the ability to do so, as they do with some crystals. They would give you a way to cancel using the obsideon/amethyst/ruby. They would set a way to use Kyanight to remove a Crystal affix you don't like, but they decided to keep a balance in the game, we would not have this ability. To circumvent the restrictions they give you in game, is cheating.