You shoot a black beam of enervating energy, sapping a creature's strength.

Make a ranged spell attack against the target. On hit, it takes 4d10 Dark damage. Then, the target makes a Constitution saving throw, potentially becoming

Enfeebled

Success. The target is unaffected.
Failure. The target becomes Enfeebled for the duration of the spell. At the end of each of the target's turns, it can repeat the Constitution saving throw against your spell save DC, ending the spell on a success.
Critical Failure (–10). As failure, except the target no longer makes saving throws at the end of its turns to try to remove this effect.

At Higher Levels: Increase the damage by 1d10 for each spell level increase.