Foster Isaac

Japanese name:	アイザック・フォスター
Nickname:	Zack

The male protagonist of the story. Once an infamous serial killer, he is now the floor master of B6. He is noticeable for his body being completed covered in bandages and wields a grim-reaper-like scythe. Bloodthirsty, Zack delights in destroying the happiness of his victims and filling them with despair. As Ray showed a severe lack in emotions, he found no interest in killing her and let her stay alive for him to use her intelligence to escape the building, in return that he will kill her once they escape.

Zack grew up only knowing how to kill due to being treated abusively as a child. Abandoned by his parents, his father tried to burn him and his mother to death, wounding his body with burns that he covered up with bandages. His mother then left him in the care of an illegal orphanage that trafficked children, where he faced subsequently more abusive treatment, becoming a tool of labour. Upon watching a slasher horror movie left by the head of the orphanage, Zack was inspired to go on a murder spree, with the heads of the orphanage being his first victims. He is subsequently found by Grey, and became a floor master.

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