Big Macintosh Apple is not a pony to mess with; an unwavering crimson juggernaut that can snap trees like tinder and rip homes from their foundations. Many ponies owe their lives to him, and more than a few denizens of the Everfree Forrest have found out the hard way that anything under his protection is strictly off limits.
But there is one race that has yet to learn this lesson, and is in fact incapable of it: the Zerg, a monstrous horde from far beyond the touch of Celestia’s sun, shaped by malice and warfare into perfect killing machines. That Equestria is safe from their reach is no small blessing, but every barrier has its cracks, and Big Macintosh is about to learn that even the smallest part of the Swarm is a force to be reckoned with.

When a supposedly-Forerunner artifact activates on-board the UNSC Guam, turning everyone on board into ponies, It sets in motion a clash of forces, ideals, and dimensions that could save humanity in its darkest hour, or doom the peaceful land of Equestria to burn in a war never meant for them.

This story starts some time before the season 2 finale, but after the other episodes of season two. Season 3 stuff will only be used if I find a reason for it/don't think it's OP (I'm looking at you Twilicorn and Mirror Pool.)
This story also takes place before Halo: Reach, so don't expect things to stick very close to the games.

Minimalistic cover art was made by me in Microsoft Paint, because I have buck-all else to work with.

Character tags will be added as they become major players.

Obligatory Disclaimer: My Little Pony Friendship is Magic is owned by Hasbro. Halo is owned by Microsoft (or some sub-company thereof). I have no stake in either and seek no profit from this work. This is purely a fan creation.