Use the following:

Roxxane: Marshtomp, Grovyle or Combusken
Brawly: Alakazam(if u have) Sceptile, Swampert(raise it to a high level)
Wattson: Swampert
Flannery: Swampert
Norman: Blaziken, Haryama
Winona:Electric Pokemon (any) and any dragon type like Flygon
Liza&Tate: Mightyena, Swampert, Blaziken must be lv60
Wallace: Groudon, Blaziken, Sceptile, Swampert
PKMNLeague with champ: Groudon, Rayquaza, Swampert, Blaziken, Sceptile