Melee Weapon Attack: +12 to hit, reach 10 ft., one creature. Hit: 26 (4d8 + 8) necrotic damage and 21 (6d6) cold damage. The target must succeed on a DC 14 Constitution saving throw or its hit point maximum is reduced by an amount equal to the necrotic damage taken. This reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0.