I did not discover it on my pokedex and I am having trouble finding one in the wild. So is there any trainer that has one?
No,there is no trainer with a yanmega in BW2.But you could always find it in Route 3 and Pinwheel forest which has a 5% chance to appear in a rustling grass.Or,you could catch a yanma and teach it ancientpower.After it learns ancient power,it will evolve into a yanmega.
Hope I helped!
i dont think so.
however you can catch a yanma on route 3 or in pinwheel forest
teach it ancientpower using a heart scale and then lvl it up once and youll have a yanmega :)
sources: experience and google