Childhood
Lillie is the youngest child of two scientists – Mohn and Lusamine. Early in her childhood, her parents were famous for both their advancements in the knowledge of multiple dimensions within the universe, and their Pokémon conservation and wild reintroduction efforts in the Alola region. Early in her life, Lillie felt like she had it all – a loving family, lovely Pokémon friends (and eventually human friends), a safe and happy place to live…. She couldn’t have asked for more.
However, one day, all of that changed.
During one of his experiments, Lillie approached the office to deliver him some food and a kiss goodnight; however, before she could open the door, a blinding bright light shone from the edges of the door and strange sounds could be heard from the other side of the door. Once it was done, Lillie opened the door to find that Mohn wasn’t there. Lillie ran back to tell her mother and brother what she saw and the trio initially went to look for him.
Mohn was never seen again.
A police report was filed and a search party was sent for Mohn, but no one could find him, and he was presumed dead; however, Lusamine refused to believe it. Over the next several years, Lusamine worked hard to pick up where Mohn left off in order to find her husband. She worked night and day to her next discoveries – about Ultra Wormholes, Ultra Beasts, and several other discoveries. Over time, however, she also began to neglect her children. She paid little emotional attention to them, forced demands out of them, and even dictated every aspect of their lives.
However, eventually they had enough. Gladion fled the Aether Foundation and joined Team Skull, and after Lillie witnessed the capture and seeming torture of a Cosmog to further Lusamine’s goals, Lillie had enough as well. She stole Cosmog away from her mother and, with its help, fled the Aether Foundation and into Melemele Island. Initially, Lillie was lost and scared on the island, but she was soon taken in by Professor Kukui and his wife, Professor Burnet. They helped take care of her and listened to her plight, but decided not to turn Lillie in for her own safety and instead label her as Kukui’s assistant.
One day, Lillie snuck off to visit Tapu Koko to pray to it; however, she and Nebby quickly were overwhelmed by Spearow and, even though two strangers helped to fend them off, she, Nebby, and the strangers were saved by Tapu Koko. Once it was over, the strangers introduced herself as Selene and Elio, and the three became fast friends. Throughout Selene’s and Elio’s journey, Lillie would occasionally meet up with them as she continued her role as an assistant to Professor Kukui; however, she was eventually captured by Team Skull and brought her to back to the Aether Foundation, and while Elio, Selene, Gladion, and Hau worked to get her back, they were unable to stop Lusamine from sapping the remaining power from Nebby and creating an untold amount of Ultra Wormholes throughout the world.
Thus, the Aether Incident had begun.
Lillie, having lost, picked up the dormant Nebby as she finally decided to spring into action. She, Elio, and Selene traveled together as she worked up the strength to confront her mother as she considered all of her options. Eventually, when she was finally ready to confront her mother, Nebby evolved into a full-blown Solgaleo! The gang traveled with Solgaleo and battled Lusamine to eventually bring her back home from the Nihilego she found herself with, and Alola was saved from the crisis with some help from the Tapu.
Post-Game
Weeks after the adventure, Lillie heard a rumor about a man in Kanto that was extremely knowledgeable with Pokémon and who may have had a way to cure Lusamine’s lingering illness from her exposure to Nihilego. So, she gave Nebby to Selene, took two of her childhood Pokémon, and took a ship to the Kanto region to find a way to cure her mother. Once in Kanto, Lillie encountered Bill, who helped to nurse her mother back to health; however, as Lusamine started to become healthy, her personal relationship with Lillie began to deteriorate. The two constantly argued over possibly returning home, even despite Lillie’s protests. Lusamine still attempted to control every aspect of Lillie’s life, even if she was not in a position to do so. Lusamine even started to leave the area and disappear for hours or days at a time, increasing how much Lillie worried about her.
Eventually, it all came to a head in one final argument between the two of them, where Lusamine attempted to force Lillie to take her home. The two yelled at each other and Lillie became so angry that she fled to the Johto Region to gather her thoughts and cry, continuing to argue with Lusamine over text as well.
Lord Rayquaza, Great Father of the Skies
One day during her time in the Johto Region, Lillie had another text argument with Lusamine. Afterwards, she found herself crying off of the shore of Olivine City. With her Pokémon gathered, she cried and wished for someone to care – wishing for someone to talk with her and take her seriously–
…her prayers were answered, just by an unlikely being.
Rayquaza descended from the heavens and answered her prayers. The dragon was friendly to her and introduced himself to her. Initially, she was baffled and on-edge, but eventually she started opening up to him. She did need someone to talk to after all.
Minutes passed as the two talked. Hours passed as they got to know each other. She talked about her past and her plights while he talked about his home and his family. She talked about her family while he talked about his own worries back home. Before long, the two talked into the night and Lillie was getting sleepy. Rayquaza helped Lillie find a place to spend the night and, the next day, the two of them worked together to find a way to talk things out with her mother. Thus, when Lillie was ready, Rayquaza helped her return to Kanto to fix her relationship with her mother. However, before leaving her side once more, Rayquaza promised that if she wishes for him again, Rayquaza will return to her no matter where she was. Thus, Lillie waved goodbye to her new friend and returned to see her mother.
Lillie did fix her relationship with her mother over the next week or two, and once it was finally clear that Lusamine was fully recovered, the two returned home in the Alola region. Everyone celebrated Lusamine’s return and Lillie was happy that all seemed to have gone better; however, for some reason, Lillie didn’t feel as at home in her home region. Even though she ventured far and wide, even after receiving Nebby back from Selene, something… still felt missing in her life.
So, a month later, she wished for Rayquaza again. She wished to see Rayquaza’s homeland – to meet the wonderful family that they talked about… to tour the places that Rayquaza loved to see…. She wished above all to live with him and spend time with him and his trainer. She hoped against hope, and yet she didn’t expect a response. She didn’t expect for him to come and hear her prayers, that he wasn’t serious about what to expect.
…she was very wrong.
Rayquaza returned to her and answered her wish. He offered to take her to the Hoenn Region and to take her under his wing and for her to start a new life if she truly wished to do so. Lillie agreed, and, after returning home and informing her family of her departure, Lillie hopped on Rayquaza’s back and flew to the Hoenn Region, where she integrated herself as Rayquaza’s new adoptive daughter. She now continues to live in the Hoenn region full-time, even though she does return to Alola occasionally to see her friends and family.