Orb of Dark Foretelling

Wondrous Item, Very Rare
These small, glass spheres appear to be filled with a translucent liquid with shimmering shapes suspended within, though the color and type of suspended shapes vary between orbs. When shaken they will briefly lumenesce.
When you take the Attack action, you can replace one of your attacks with throwing the orb, which bursts on impact. Target one creature you can see within 20 feet of yourself. The target must succeed on a Dexterity saving throw (DC 8 plus your Dexterity modifier and Proficiency Bonus) or become temporarily cursed. For the next minute, attacks against that creature have advantage. In addition, the creature has disadvantage on the first saving throw it makes within that minute.
If the creature succeeds its Dexterity saving throw, roll 1d20. On a 20 the orb lands safely 1d6x5 feet away and may be recovered. On a 19 or lower the orb bursts on any surface or object it hits and is destroyed.