Kusen

Background
Prior to his death, Kusen was the administrator of the Tower of Desire, portrayed as a calm and collected, but strict, old man. In his life, Kusen was a staunch believer and advocate of class supremacy; this personal disposition of his was very clearly reflected in the way he managed the tower and everyone in it, subjecting everyone, guests included, to class based discrimination.

His belief in class supremacy was also secretly put into action in the form of the experiments he conducted which sought to suppress and permanently remove the slaves' ability to use and practice magic, fearing that as long as they could do that and with their large numbers, they would continue to pose a threat to the ruling nobility class.