You can reach this snazzy area from the east side of Route 6. First, head east to reach the Pokemon Center and give your Pokemon a breather if they need it. For those swimming in dosh, the right clerk at the Poke Mart is selling weather-based TMs for 50,000 Poke Dollars each.
Having cleared Lana's trial, the standard (left) clerk at all Pokemon Centers will have new items in their repository. Most notably, you can finally purchase Revives. Back outside, continue east to reach a pretty park. Towards the bottom of the flower garden is a Photo Spot.
The sparkling spots among the pink floors yield Pink Nectar, which can be used to change Oricorio to the Psychic/Flying Pa'u Style. The Melemele Pom-Pom Style is pretty much the best though. If it's night, you can find a Zygarde Cell (21) chilling in the north-west corner of the park.
Moving on, further east is the malasada shop. Before entering, search the pile of junk to the right for a hidden Rare Candy. What's this, a dessert before the main course? Inside, you can order Sour and Dry Malasada for your Pokemon or a big one to take out.
An Acquired Taste
Pokemon will adore Sour Malasada if they have a Nature that boosts Defense, while Pokemon with a Special Attack increasing Nature will prefer Dry Malasada. Pokemon gain more friendship (confusingly called "affection" by the game) if they are fed a Malasada they love.
That's the first half of the exploration over. To advance the story, head north from the flower garden. You'll see Gladion entering the Battle Royal Dome. Before you follow him in, follow the tarmac west. At the end, head north through the gap to retrieve the Ultra Ball.
Inside the Battle Royal Battle, step forward to receive a Battle Royal lesson from Professor... er, we mean the Masked Royal. In a Battle Royal, four trainers compete simultaneously, using three Pokemon each. The match ends after the round when one trainer has no more Pokemon.
At this point, the trainer who has knocked out the most opponents and has the most Pokemon still remaining wins the bout. For your introductory lesson, you'll be facing off against Pr... ahem, the Masked Royal, Hau and Gladion, each using one Pokemon.
Now the outcome of this battle doesn't matter, so just go crazy and have fun. The Masked Royal uses Rockruff, while Gladion uses Type: Null and Hau uses his starter Pokemon. You'll automatically use your first Pokemon; so hopefully you set it to something decent before entering.
Afterwards, you can leave or hang around. To participate in an official Battle Royal, chat to the receptionist to the left of the PC. The other receptionists let you buy rare items using Battle Points (BP) earned in Battle Royals or other means.
Outside, follow the tarmac east towards the car park. If it's day, go around to the parked cars. Between the blue and red truck is a Zygarde Cell (22). Towards the south-east corner are a pair of punks squatting on the floor. Search the corner to their left for a hidden Soda Pop. Theirs perhaps?
Next, head north and check out the big building east from the Battle Royal Dome: Thrifty Megamart. Inside, you can buy some items for a cheaper price by speaking to the checkout operators along the front of the store. The left-most operator won't do anything until you're the Champion though.
Whether you're here to buy or not, head along the east-most side of the store. About halfway up, chat to the Drifloon accompanying the little kid by the frozen section for a free Lemonade. Also, you can get a free berry once per day from the stall in the south-west corner.
Back outside, continue north, east from Thrifty Megamart to reach the exit.