>>21953219Use the PC in your secret base, there should be an option like Manage QR Codes or something. Scan the codes with your 3DS, and the bases will appear in your game. You won't be able to battle them until the next day, however.
Once you get to the Battle Resort you can get a decoration called a Level Release that allows you to remove the Lv.50 limitation on secret base battles, making the Blissey Lv.100 and netting you more Exp.
I know for a fact the teams in
>>21952744 all use Blissey that only know Healing Wish and hold Toxic Orbs, so you can bring a team of 6 Lv.1 Pokémon if you wanted to and just wait until they die from Toxic damage. (Make sure you have Exp. Share on so everything gets Experience.)