Here's a dilemma that I've been working on ever since my first words hit the page for my original story. Should I add Aliens??? Here's a specific reason why I had added them and then taken them out: At first, they were there as a means to an end because they were known for their ability to find ancient artifacts and restore their power to do ungodly things with them, such as harvest planets, create and destroy matter, and even convert life into multiple forms. There was one such artifact I called "The Water Matrix" simply because it had the power to restore life in brilliant (and vibrant ways.) But since removing this to make the story more about humanity and less about outside entities and subjects, I haven't found a use for aliens. But my biggest issue is finding an enemy. I know a lot of popular science fiction today relies on Alien adversaries for the majority of the plot. Look at titles like Halo, and Prey (the video game.) Star Wars, on the other hand, has an assimilated feature with alien races that resemble humanity very closely. I've been looking into making a human approach to war since it seems very likely. So I guess my question is: Under what circumstances would an alien race be applicable for a story that is heavily grounded in humanity?