Blue in the sky

In a distant future, humanity managed to find a new home, on this new planet society lives in the nostalgia of ancient times, it has developed well, until a threat attacks this new civilization, Ghosts are creatures with dark blue bodies almost snatched the world, but Holdfighters appear as a silver light breaking through the darkness of the Ghosts in a fight that takes decades, in this bellicose world our hero seeks his goals against this "space nightmare".

I didn't decide on the Prompt yet, but I believe this Prompt is the most accurate for my first story, sorry if my writing is not so good.
Prompt: When the Clock Strikes Midnight
Theme: #Mystery
My Theme(s): #School, #Mecha, # Sci-Fi