She appeared in The Case Of The Kidnapping Josie! where she had a double battle with Lusamine and her Milotic and Clefable combo, but she was quickly defeated by Milotic's Hydro Pump, and Clefable defeated Klang with Flamethrower due to Metronome and Josie was taken by Lusamine and caged her leaving Delphox to escape to find help. After Josie and her family was kidnapped by Lusamine and Jon was also caged up, Delphox was able to free them with Flamethrower along with Josie's Tsareena who used Trop Kick on the cage to free Jon.
Josie explained to Jon that Delphox was originally a Fennekin during her time in Kalos before she evolved into Braixen and later into Delphox.
In The Rescue Operation!, She then undergoes a special form called "Josie-Delphox" and confronts Lusamine. Jon states that his Typhlosion can do that Bond Phenomenon as well.
She was used again in the Ultra Space when Lusamine lost control of herself after merging with Nihilego and her Pokémon felt the same effect. She and Typhlosion teamed up to defeat Lusamine. Jon's Pokémon and her Pokémon took part of the battle.
She was later used in Alola Defence Deploy! where she took part of the battle against Ultra Necrozma, and learning Blast Burn in the process.
She later was used again Jon in the Alola League as her final Pokémon and going into Josie-Delphox against Jon's Typhlosion, it was a very long and close battle, but she took the most damage than Typhlosion did and was defeated, making Jon declared the winner and the Champion of the Alola League.