Lily has the power to read Pokémon's aura. Because of this power, she was kidnapped by Team Galactic when she was only five years old while playing a game of hide-and-seek with Hiori and his Riolu. Lily was shown to be at a high rank in Team Galactic, working along with her section leader's second-in-command and receiving missions from her in person.
Lily as a member of Team Galactic
In her first appearance, she was being chased by Pokémon 7 and Rocco for stealing a woman's Chingling. However, her brother's Lucario was unable to read her aura due to a special cloak made by Team Galactic. Later, it was revealed in a battle with Pokémon 7 that she had lost all memories of before she was kidnapped and is currently being brainwashed by her Mismagius.
After winning back her memories, she revealed that her section leader, Io, captured Darkrai and was planning on using its powers to take over the world. She, along with Hiori and Rocco, found Darkrai in captivity under protection of Io and her second-in-command. They defeated them both, but not until after Io awoke Darkrai, causing it to go on a rampage. They eventually calmed down Darkrai enough to set it free. but was caught in a cave-in caused by the battle. She was later revealed to be alive and well a month later roaming the world with Rocco and Pokémon 7 after the former saved them all with his Gardevoir.
Leafeon was a Pokémon that was originally Nazuna's but was given to Lily to help her battle against Team Galactic. She used her in a battle against the #2 Galactic member where after a tough battle, they manage to defeat him and his Rampardos.
Dusknoir was a Pokémon that was shown in Lily's possession when she was a member of Team Galactic. She used it in a battle against Hiori and Rocco where it was defeated (inadvertently) when it was poisoned by Rocco's Magmortar's Smog.