Wretched Sorrowsworn

The sorrowsworn has advantage on an attack roll against a creature if at least one of the sorrowsworn's allies is within 5 feet of the creature and the ally isn't Incapacitated. The sorrowsworn otherwise has disadvantage on attack rolls.

Melee Weapon Attack +3 to hit, reach 5 ft., one target. 6 (1d10 + 1) Piercing damage, and the sorrowsworn attaches to the target. While attached, the sorrowsworn can't attack, and at the start of each of the sorrowsworn's turns, the target takes 6 (1d10 + 1) Necrotic damage.
The attached sorrowsworn moves with the target whenever the target moves, requiring none of the sorrowsworn's movement. The sorrowsworn can detach itself by spending 5 feet of its movement on its turn. A creature, including the target, can use its action to detach the sorrowsworn.