Our Last Crusade or the Rise of a New World, Vol. 6 (light novel)

Summary

When Elletear finds out Sisbell's new guard is an Imperial solider, she holds this secret against her younger sister, caging Sisbell and Iska in the royal villa to prevent them from interrupting her plans. After all, Elletear is the one suspected of colluding with the House of Zoa to organize the coup unfolding in the palace. Afraid for Sisbell's life, Alice races over to the villa to put a stop to Elletear's deeds...forcing all three sisters to come together under one roof for the first time in a long while.