I ask this question as I have not Groudon and Kyogre yet.
But when both trainers use as their first Pokemon Kyogre and Groudon (or their Primal form), which ability is activated first (and will be useless then) ?
Is it the same with Kyogre VS Rayquaza or Groudon VS Rayquaza ?
As with all abilities that activate immediately upon entering battle, the ability that shows up first depends on which Pokemon is faster. The faster Pokemon's ability will activate first.