As harsh as it sounds, a metagame like Anything Goes severely punishes poor team options. Roughly half of your team will get steamrolled by Mega Rayquaza, and your team lacks any sort of offensive presence barring Mawile.
I can see Mawile as a justifiable option, but everything else is horribly outclassed. Why run Reuniclus when you could instead run the myriad of Psychic types available? Why Milotic when Palkia and Water Arceus are better bulky water types?
And, not to be rude of course, but Ledian and Magcargo? They're among some of the worst Pokemon in the game.
Why does Mawile have Foul Play? It uses the opponent's attack stat, not yours.
You'll have to rework this team pretty significantly for it to work. Fizz and sumwun's comments are pretty spot-on, too.
