If Ponyville's new repair-pony gets his way, the Mane Six won't even know he exists - and nopony in Ponyville will miss him for long once he's returned to Earth.
Discord makes a deal with an anonymous human. The human gets to live a good life in Equestria. And Discord? he gets to have a son of his own. Of course, his only reason is to impress Fluttershy and annoy Twilight.