I could say that evil is in the eye of the beholder. But I couldn't say for sure without asking the beholder. What would Midnight say if pressed to justify that his attack was good and Sombra's defense was evil? One could reasonably say that an empire cannot be evil unless it does evil, and that as the Crystal Empire takes no action at all outside of its walls it cannot be doing evil to the outside world, so it can only be evil if it does evil internally. Would he argue that the Crystal Empire is doing evil to its citizens, or would he dispute the logic that told us that's the only way for it to be evil?