I'd want to be the Sinnoh champion because they were the ones who challenged me the most and who I had the most fun battling.
I'd have a mix team since being type specific would probably be too easy to fight, granted I am no expert.
My team: Meganium (always loved them) Vaporeon (my favorite water pokemon) Vanilluxe (comedic value and I like them) Chandelure (I always use a current gen ghost) Skarmory (I always liked that steel flyer) Lickylicky (just cause)
The voices in my head may not be real, but they have some good ideas! <(^_^<)(>^_^)> Official Yarne of the FE: Awakening Board! Bunny monster!!!