Umbral Grasp

Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 18 (4d6 + 4) cold damage and the target's Strength score is reduced by 1d6. The target dies if this reduces its Strength to 0. Otherwise, the reduction lasts until the target finishes a short or long rest. If a non-evil humanoid dies from this attack, a shadow rises from the corpse 1d4 hours later.