Since you were the runner up of the last tournament, and Tabuu is for sure not participating, you get the tournament advantage!
Your advantage is pretty damn cool. You get to use 2 permanent weather inducers on your team. They both have to have the same ability (meaning you can't have a dual weather team), but this allows you to have a backup Pokemon if one of your weather inducers faints. You can choose not to take advantage of this advantage, but I recommend you do, since it's a pretty big advantage.