[Crossover, Halo.]

Equestria was at peace for the first time in years after the battle with Tirek. Now after a few years a new enemy appeared. The Covenant, aliens that came from space to destroy there plant and everyone on it, but those who didn't want to just sit around and die took up arms to defend there home and there family's. Unknown to them a certain Sparten is stuck in there world as much as they are with the war.