|Grace Mirchea Luslec|
|Korean Name||그레이스 미르치아 루슬렉|
|Sobriquet||Heretic (Tiger Fish)|
Although FUG’s true motives and goals are not clearly known, it is true without a doubt that they exist in the shadows of the Tower, hiding and corrupting. People call Luslec the "God of the Devils" (악마들의 신, Ahkmahdeuleui Shin) or "Demon King"(마왕, Mahwahng; 魔王).
Luslec was one of those that helped the 10 Great Warriors climb the Tower. No one knows how or why he has fallen to becoming the leader of a such a dangerous group; although the author hints that it has something to do with how Zahard became king.
Apparent in his ranking, Luslec is a powerful warrior. They say that there is nothing his great black Hook can't pierce.
Even though the FUG has dangerous status, the influence of Luslec's group can never surpass the Family Heads of the 10 Great Families, as long as they hold contracts with the Tower's Guardians.
Nevertheless, Luslec holds a rank that surpasses a few of the Family Heads. This is because he represents the "Absolute Darkness" of the Tower. He aims to kill Zahard.
In Part II, it is revealed that Baam has joined FUG and adopted his family name.