Slightly alternate timeline of the Human-Covenant War (and the events following it). For instance, the URF is much more powerful as a faction in this story. Also, most of the characters are original - however, there will be existing characters making an appearance.
There isn't going to be a big focus on Spartans in this story. It's primarily about more conventional and unique UNSC elements, and explores UNSC/Human society during the Human-Covenant War and tries to paint a realistic, dark depiction of what life would be like.
As such, it's rated M. There are a lot of graphic scenes. And since most of the characters aren't spartans, Im trying to make them feel real. So they get wounded, they hold grudges, they have personal vendettas, some of them have psychological issues (including the main character), they get caught between difficult moral conundrums and so on.
