Mad that rich and powerful pokemon were taking advantage of the weak, Lilly became a thief to deal with it and wander around the world helping pokemon in her own way, taking from the evil and corrupt and giving it to pokes who need it. Over time she met a Weavile named Lilith who, just like her, wanted to help the poor. They formed a team and worked together to become the best thieves in the world that no one could ever beat. Many years later the two would found both the hidden Thief Village and the Thieves Guild, starting the creed “A true thief steals from criminals and the corrupt. There is no challenge in stealing from the innocent.” and the two would become sworn sisters. Lilith would later give her a Shiny Umbreon named Zira who was an ex-thief of the Thief Guild but left to help her homeland from war. Lilly is happy to have her as her diaper and thanks to Zira she no longer has a weakness to Psychic-types and was given better Defense and Sp. Defense.