Kanae, Keeper of the Gates Emblazoned
They could have it be 3v1 like Nanu had against Ash, except Ash would have the number advantage this time.I'm pretty sure the exhibition match is going to be a 1x1 against Masked Royal, because Masked Royal hasn't been seen with any other Pokemon except Incineroar. And the reason that Incineroar is so strong is Kukui overleveled it as his starter.
I know the opening shows Pikachu vs. Incineroar, but I can't imagine it being a 6x1 so Pikachu and Torracat both gets reps in. That would be really ridiculous for a Pokemon battle. Even the ring matches where Incineroar knocked out Decidueye, Primarina and Machamp was partially intended as an over-the-top joke.