Homebrew:8-Scream Devil Powder

Wonderous item, uncommon

A parchment packet sealed with beeswax. As an action, make an improvised thrown attack against a creature within 20 ft. to throw the packet.

If the attack hits, it bursts and the powder swirls in the air around the target, following the target if it moves. At the beginning of your next turn, the powder seeps into the target's skin (creatures without skin are immune).

If the attack misses, the powder fills a random 5 ft. cube somewhere along the 20 ft. line extending between you and the target (not including your own space or the target's space). The powder persists in that space for 1 minute, or until a creature starts its turn in that space. If a creature starts its turn in the powder's space, the powder seeps into the target's skin (creatures without skin are immune).

Creatures affected by the powder have disadvantage on attack rolls and saving throws. This effect persists until the creature takes acid damage, they spend a short rest cleaning themselves of the powder, or they take a long rest.