Necropotence

The necromantic potence of your dark magic carries with it a haunting curse. You gain the following benefits:

• When a necromancy spell that you cast deals necrotic damage to a creature, that creature's hit point maximum is reduced by 1. If this effect reduces a creature's hit point maximum to 0, the target dies. This reduction lasts until the creature finishes a long rest or until it is removed by greater restoration or similar magic.
• When a creature uses a spell (such as greater restoration) to remove any affliction imposed by this feat or by a necromancy spell that you cast, the creature who casts the spell takes 2d4 points of psychic damage.

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