In Pokemon X, I'm trying to get a Lairon so I could evolve it into Aggron. But: ALL OF THEM ARE ABOVE LEVEL 42. How do I get my Lairon to evolve into an Aggron?
FYI, I'm saying it's possible to have your Pokemon not evolve by holding the B button so it could learn moves earlier. And in that case, do what GameFreak said - level it up again and it will evolve.