An experimental self aware A.I. driven robotic soldier named Adam is told he's been ordered to be destroyed by the government... His creator frees him from his military directives and tells him to run. He has a new directive now, self preservation.
A crossover with Halo. The Forward Unto Dawn crash-lands in Equestria more or less intact. The Master Chief and Cortana are then dead set on finding something on this strange planet that will help get them home.
After a 300 year journey the Guardian of Equestria returns, only to be greeted by a very different world. Surviving is one thing, being hunted is another.