The Heavenly Fox Clan's control over Luck is well-known to be incredibly powerful. The Bead of Misfortune, the reverse of the Heavenly Fox, is undoubtedly a divine tool among divine tools.
Imagine, if during battle, one used the Bead of Misfortune to inflict misfortune on an opponent, especially misfortune at the Great Demon King Level, how could the opponent continue to fight? They would probably not even be able to exert half of their own strength. And this is considering an opponent of the same Great Demon King Level. If one were to face a lower-level opponent, they would likely be directly devoured by the misfortune.
