The case containing Fennekin's Poké Ball and Pokédex were taken to the Team Flare Secret HQ, along with other Poké Balls taken from Vaniville Town. When Malva returned to active duty as a member of Team Flare in Dancing Vivillon, she dug through the collected Poké Balls and found the case with Fennekin inside, deciding to take her for herself while smashing the unneeded Pokédex under her shoe. Later, Malva informs Celosia about Team Flare's plan to retrieve the dormant tree form of Xerneas in order to power the ultimate weapon. After both sides separated to begin the operation, she was released out of its Poké Ball, revealing that she had evolved into a Braixen at some point.
As a Braixen
In Changing Gengar, the battle for the dormant Xerneas went on, and Malva and Braixen were seen observing from the trees as Celosia and Essentia fought against X and his friends in order to stop them from interfering with the operation to take Xerneas. When Korrina, Gurkinn, and Diantha appeared to help, Malva decides to step in to fight as well and beckons Braixen to join. Malva chooses Diantha as her opponent and has Braixen use Magic Room to surround them both in a giant sphere that isolates them from the outside. Malva notes that her plan was to use Magic Room to try and prevent Diantha's Gardevoir from using Mega Evolution, only to find that move has no effect on Mega Stones. Despite this, Malva continues to order Braixen to furiously attack and trap the KalosChampion. As they battle, the Magic Room begins to sink into the ground. Y and Shauna attempt to stop this, but are unable to break open the Magic Room barrier before it fully disappears. Later, Braixen is seen with Malva watching Lysandre train in the Pokémon Village.
In Charizard Transforms, at Route 10 she is revealed to have evolved into a Delphox. There, she oversees a group of Team Flare Admins and Grunts tying captured Pokémon to the prototype Absorbers that line the area. When she passes by Shauna's Furfrou, the Poodle Pokémon recognizes her from the Vaniville Town incident and calls out to her, only to be ignored. After the Pokémon are put on the Absorbers, their life energy is drained to power the ultimate weapon. The Admins are horrified by this event, but note that Delphox is completely unfazed, which reminded them of Malva. Soon after, Delphox notices that intruders have arrived in the area and pulls out her branch to begin attacking. However, as soon as the branch is lit, the flames react to a Vivillon's Powder, causing a gigantic explosion. The intruders then appear, revealing themselves to be Viola, Alexa, Clemont, Bonnie, and Yvette.
The intruders begin attacking the area in an attempt to free the Pokémon tied to the Absorbers. Despite her attempts to stop the intruders from interfering with her powerful attacks, Delphox is unable to stop the captured Pokémon from being freed. After some time, Delphox and the rest of Team Flare are defeated. As she lays on the ground unconscious, Shauna's Furfrou looks upon Delphox with pity.
After Team Flare was defeated, Clemont gave Trevor a Poké Ball containing the unconscious Delphox inside. Clemont revealed that after Team Flare's defeat, Shauna's Furfrou protected the unconscious Delphox, which clued Clemont into realizing that Delphox must have been related to X's group somehow. Trevor then decided to have Delphox join his group of friends.
Personality and characteristics
Malva's ownership seems to have had an influence on Delphox as when she was Braixen, she is willing to follow her orders to assist Team Flare without any hesitation, such as when she trapped Diantha and her Gardevoir with Magic Room. This behavior has been noted by two Team Flare Admins, having seen her completely unfazed from watching the Pokémon's life energy drained to power the ultimate weapon. It is unknown how she behaved prior to coming under Malva's care, however she was shown with a constant smile before being lost.