Unfortunately, that is not the problem.. Shes the only one with Eviolite, and the message i get says that I have a pokemon that cant participate. Shes 100% legal, hatched at the battle resort, all natural ORAS pokemon... Just has fake out, rapid spin, scald and protect along with rain dish.
-Do all of your Pokemon have different items?
-You're not using any two Pokemon of the same species (ex. two Wartortles)?
-You're not using any mascot/mythical legendary Pokemon, or any other Pokemon that are banned from official Nintendo formats?
-All of your Pokemon were obtained in Gen VI, with the pentagon on their summary screen (if you're playing ORAS)?
If you've answered yes to all these questions, then odds are a Pokemon in your party is hacked, and is being blocked by the hack-checks of Battle Spot. It may not necessarily be the Wartortle, but something else on your team. I'd suggest taking each Pokemon on your team in one at a time with 5 other Pokemon that you know will be allowed online, to weed out the culprit.