>Do you play Ubers? Unless you play in Ubers, Primal Groudon is not a problem. Mega Rayquaza was banned from Ubers, so you shouldn't need to worry about that at all.
commented 40 minutes ago by ƒιzz
He's right. Unless you run into Golduck with Cloud Nine, you should be fine.
On the DS, assuming this is Battle Spot legends aren't allowed. You should be safe unless another Pokemon with Snow Warning or Drought comes in.
Hope I helped!
-It's a secret!