Saw Tasting History, so now I have an idea for today!
Casting Time:1 action
Range: 200 feet
Components: V, S, M (arrow head made from a fingernail)
You throw the arrowhead at a target in range making a ranged spell attack. On a hit, the target is pierced by the spell. Unless someone directly sees you throw the arrow, the target does not know they are affected. Each day at moonrise, the target must make a Constitution saving throw. On a failure, the target gains one level of exhaustion. This level of exhaustion can not be removed until this curse is lifted or the spell ends. If the target dies from this spell, no wound is found on the surface, but a hole from an arrow will be found inside the target.
The spell can be recognized with a successful Intelligence(arcana) or Wisdom(medicine) check. You can end the spell by making a Wisdom(medicine) check using the plants feverfew, red nettles and waybread as components in the treatment. A remove curse, greater restoration, or wish spell also ends it. In either case to end the spell, you must be aware that the target is affected by this spell.