After she has just announced becoming a Half Primordial, Appep had requested a private meeting with her and Lucie didn't refuse as she too wanted to know what he wanted to talk about and she wasn't disappointed. The
All along she was not pleased with being under Lilith's rule as they were of the same generation and used to study together as they were kids, her pride refused to bend to that but kept herself in check as she didn't have enough strength to fo against Lilith over the throne, but her success to Half Primordial realm gave her confidence to challenge Lilith.
Being the smart woman she is, she knew she wouldn't be able to do it alone and had a plan to invite the other unhappy Sin leaders to would accept her cause and these were none other than Satan, Leviathan, and Mammon.
