Niko Bellic. He was a well-known criminal in the underworld of Liberty City, but after he killed his crime bosses, he seemed to disappear entirely, only popping up here and there for a car theft or gunfight. He was the best of the best, so you can imagine his surprise when a bomb went off, and he sank to the bottom of the ocean, apparently drowning.
Or at least, he thought he had drowned.
When Princess Luna and Princess Celestia decide that they want to reform Niko so that he helps the world, they chose none-other than the Element of Laughter, Pinkie Pie, to do the job. While Niko tries to continue his normal life with the addition of this new companion, Pinkie shows Niko that there is something more powerful than money, crime, and death. Something that even he can muster up inside of him and use against his foes. If he survives the pony herself, that is.