I will never understand the need of some fiction writers to explain their story early on, and make their readers understand what's happening in their story before the story begins. You're not writing a scientific explanation of what happened and why, you're hopefully writing a darn good yarn that keeps your readers guessing until the very end. At least that's the way I see it.
When you write a prologue, or dump backstory in the first chapters, is your intent to give the reader information that your MC doesn't have? Where's the fun in that? The only good stories I've ever read, or seen, or heard, have the audience unraveling what's going on along with the MC. Who are those things dressed in black? Where do they get their powers? What about those others? And what is it with those dove pendant things? Now, when I have answered these questions, how do I use what I've discovered to save the lives of me, my loved ones, humankind, the universe.
Why on God's green earth (sorry, got a little dramatic there) would you want to try to answer these questions for the reader before the story begins. I just don't get it.