What happens if you use Primal Groudon & Kyogre and Mega Rayquaza in a triple battle or rotation battle?

Question

For double battle, what about Primal Kyogre and Primal Groudon? This is a very important question to me.

Answer 1

In a Rotation Battle, Desolate Land will not activate if the Pokémon is sent out in a rotated-out position, nor will it activate if the Pokémon is rotated in.
If a Pokémon with [a weather-affecting ability] is sent out in the same turn as another Pokémon whose Ability affects the weather, the slower Pokémon's Ability will override the faster Pokémon's Ability.

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