Kusogaki Shackles is an item that reduces the negative effects of other items. It is unlocked by surviving for 10 minutes as Murasaki Shion in a single run.
Halu is not affected by the Shackles, since the Shackles only affect negative effects on the player, and not any bonuses to mobs.
Negative effects of skills like Minato Aqua's "Klutz" are unaffected, since the Shackles only affect items.
Trivia
The item is a reference to La+ Darknesss based on the shackles on her neck, arms, and ankles, which in her lore are supposed to keep her powers in check.