Marcus is dead, the resistance has been crushed, everyone has been ponified, and earth has been completely terraformed.

When Trevor Phillips, a man who is so angry, so manic, was ponified, the potion only worked on him physically, turning him into a simple orange earth pony. In his mind however, he still is just as homicidal as ever. He's been keeping it under check, pretending to act like the new ponies, cursing how violent he once was. But it's building, his inner rage. And soon, it's going to burst.

This story is based around those Rampages Trevor has in the new GTA, and the Conversion story written by redskin122004.

I literally thought of this while sleeping.

http://www.fimfiction.net/story/42449/the-conversion-bureau-the-other-side-of-the-spectrum

GO READ IT IT'S SO GOOD