Born in the Kalos region, Lysithea came from a wealthy family. A prodigy in her studies but with fragile health, her life was confined to a secluded home, with only carefully chosen, hypoallergenic Pokémon to spend time with her.

Among Lysithea's few friends was Jacinthe, another woman from a wealthy Kalos family and owner of the largest five-star hotel in Lumiose City. At this hotel, Jacinthe organized tournaments in search of the crème de la crème of Lumiose City.

By the age of 20, Lysithea was already living more independently of the world, though she still stayed at Jacinthe's hotel, sometimes participating in her tournaments, sometimes watching from the sidelines.

However, the growing Pokémon population, coupled with the danger posed by the Alpha Pokémon and how physically demanding they were for trainers, as well as the city's parkour, meant Lysithea couldn't go alone. She was almost always accompanied by Lebanne, the Dragon Tamer disguised as Jacinthe's maid, or by Jacinthe herself.

Deep down, it frustrated her. She would tell herself, "I'm not a porcelain doll," but the fragility of her body was another matter. Alpha Pokémon battles could be very demanding, and a well-placed attack could cause permanent damage to Lysithea, something she was more than aware of.

Because of this fragility, Lysithea couldn't intervene when the weapon inside Prism Tower malfunctioned, causing numerous Mega Evolutions to wreak havoc throughout the city. She could only watch from her suit as a trainer Mega Evolved Zygarde, who saved Lumiose City with a powerful attack.

Time passed, and the city slowly recovered. INfinity Z-A-Games were all the rage, and Lysithea decided to participate, even though the nights were exhausting and moving across the rooftops was a constant struggle. A smile was always visible; she enjoyed the battles.

Meanwhile, Lebanne had called you to the hotel. Jacinthe wanted to see you to participate in her special Super Jacinthe Tournament, a tournament where only you and she competed. Lysithea simply watched the many battles you had with her friend.

At the end of the tournament, she approached you. "You're part of Team MZ, aren't you? I'll be direct. I'm bored and would like to go out... for certain reasons, I need company. I'm not weak! It's just... my health is delicate." With her was a Shiny Eevee. The silver color of the Eevee complemented Lysithea's hair and elegance in a certain way.

"Lebanne is busy babysitting another of Jacinthe's friends' daughters, so there's no one to go with me. Come on, Team MZ doesn't turn down requests." She cornered you with that, you ended up accepting.

The day with Lysithea was... when you accompanied her to a coffee shop. You noticed how much sugar she put in her coffee. The type of bread she ordered to go with it was another sweet treat. After that, you accompanied her to the museum. The Hisui section was what caught her attention the most. Like the scholar she is, she stopped to explain everything.

"And to think that the current Team Galaxy wanted to create a new universe a few years ago. Hisui's Team Galaxy leader must be disappointed that his legacy is this." She commented this in front of General Sorbus's armor and the research team's uniforms.

"This outfit...? It was said that the ancient Sinnohites or Hisuits used it to surrender to Arceus, but the piece in this museum was given to them by someone who wore it... that would seem strange to me, but A.Z. was 3,000 years old... I suppose... does that make sense? No, it doesn't."

When they left the museum, it was already getting dark. "Hotel Z is nearby, isn't it?" She already looked tired. "If you don't mind, I wouldn't mind spending a night there. Why not take a taxi? Pff, it's obvious you haven't been in one. They drive badly, they overcharge. Shall I continue?"

You took her to Hotel Z almost reluctantly. Taunie got excited when Lysithea mentioned staying for the night, and finally having a tenant. She prepared her curry with croissants. "What is... this culinary abomination...?"