Dendemille Town

As you enter town, you will meet Professor Sycamore and Dexio. They will tell you about yveltal. After they leave, Trevor will arrive and tell you that he will go to the Frost Cavern.

Once they leave, head south. Past the bridge is the gate to Route 17, but you will not be able to enter that area yet. Talk to the hex maniac near the Pokémon Center. She will sell Moomoo Milk for P500 a bottle. Moomoo Milk heals 100HP. Buy some for your trip as it is cheaper and better than a Super Potion(costs P700 and heals only 50HP). To her left, in front of the Pokémon Center is a hidden Heal Ball.

Enter the Pokémon Center and talk to Mr. Bonding in his usual spot. He will give you Accuracy Power. Head to the east portion of the Pokémon Center and talk to the lady near the bookshelf. She will give you a Sitrus Berry.

Backtrack then head to the right this time and enter the lone house. The old man to the left is the Move Deleter. He can make your Pokémon forget moves, even HM Moves. The old lady to the right is Madam Reminder. In exchange for a Heart Scale, she will remind your Pokémon of a past move that it was capable of learning by leveling up. Wild Luvdiscs sometimes hold Heart Scales. They can be located in the waters of Cyllage City, using an Old Rod. You may either use the move Thief on them or just catch them.

Directly to the south of the house is an empty field. There is a Big Root here as well as a hidden Nugget in the middle of the lower left patch.

Head back north and climb up the stairs. Stick to the right and enter the house and the end. Talk to the old man and he will give you a Shell Bell if you have seen more than 70 Pokémon from the Mountain Kalos region. Shell Bell recovers a little bit of HP if the holder inflicts damage in that turn.

Exit the house and head west. Ignore the other house and use your dowsing machine in the area next to it. Locate an X Speed in the corner of the railings. Head all the way south and enter the house.

The kid to the left will give you TM42 Facade. She’ll ask you if you have a certain TM. She will give you a Leppa Berry if you have what she is looking for.

Leave and head back to the town’s entrance. You can use the path to the right of the house in front of the windmill as a shortcut.

After you have rested and restocked, return to Route 15 for the optional Lost Hotel. If you want to continue with the story, you may take the bridge in the northern part of town to reach Frost Cavern.