Orim of the Shadow:
To lock the devil Zeruel back into the box, we need to have 2 things. One is the Sword of Binding, and the other is the Soul-trap Crystal.
Sword of Binding belongs to Sir Klaus Vasper, and the Soul-trap Crystal is owned by Master Iker of Giran. Neither of them are in favor of Witchcraft, so it won't be easy win their cooperation.