Lonely Sorrowsworn

Traits

Psychic Leech. At the start of each of the sorrowsworn's turns, each creature within 5 feet of it must succeed on a 15 Wisdom saving throw or take 10 (3d6) psychic damage.

Thrives on Company. The sorrowsworn has advantage on attack rolls while it is within 30 feet of at least two other creatures. It otherwise has disadvantage on attack rolls.

Actions

Multiattack. The sorrowsworn makes one Harpoon Arm attack, and it uses Sorrowful Embrace.

Harpoon Arm. 7 to hit, reach 60 ft., one target. Hit: 21 (4d8 + 3) piercing damage, and the target is grappled (escape 15) if it is a Large or smaller creature. The sorrowsworn has two harpoon arms and can grapple up to two creatures at once.

Sorrowful Embrace. Each creature grappled by the sorrowsworn must make a 15 Wisdom saving throw, taking 18 (4d8) psychic damage on a failed save, or half as much damage on a successful one. In either case, the sorrowsworn pulls each of those creatures up to 30 feet straight toward it.