2nd-level / Shadow Hand
A faint nimbus of sickly gray shadow surrounds your weapon. When you attack, this shadowy aura flows into the wound you inflict. As part of this maneuver, make a melee attack. If this attack hits, you deal damage as normal and the target must succeed on a Constitution saving throw or its maximum hit points are reduced to its current hit points. The maximum hit point reduction is applied after the damage.