He will probably use his strongest. Infernape, Sceptile, Snorlax, Heracross, Swellow, Charizard(Maybe and Hopefully), you know the usual suspects. Although he will, or should make a diverse team. I liked what they did in the Sinnoh league, where he used different teams of Pokémon, that was great and they should do that again with the Unova Pokémon. Although I would like to see Totodile or Quilava evolve, heck I wouldn't mind if Gible evolved either. To a certain extent I would like to see kingler and Muk participate again, they deserve it and both were powerhouses in the indigo plateau in case anyone forgot. Last but not least, when the hell are you going back for Pidgeot, I know the writers will never do this since they like breaking the fan's pokballs, but come on, it would be awesome to see Pidgeot in a battle, specially at a league.