Han Jihye narrated a riveting story about how much she was wronged when she first came to the Manipulator's Guild. Even though the other Undying received so many benefits, almost always, the former Guildmaster would exclude her.
She thought that it was just a coincidence, that her turn was coming soon, but her hopes were dashed when she realized that the Guildmaster was actively trying to mess with her progress, giving her the simplest jobs and Divine Trials and allocating the least amount of resources to her.
Since Jihye knew that her future wouldn't be bright if things went on like this, she decided to take matters into her own hands.
This and that happened, and she received the skillset of a human Manipulator.
She didn't speak about how exactly she took control over the three Guildmasters, but she allowed Lorn to reveal her skills.