Personally, I think X&Y could have been the end of Ash's story had he learned to Mega Evolve and had brought back Charizard and Sceptile. He would have won the Kalos Conference had he used those two. Would have been a good note to end Ash's story on. Finally winning a legitimate league (I don't count the Orange League, since it only has 4 badges; and the Battle Frontier isn't really a "League").