Enervating Light

You conjure a mote of sickly light at a point within range. The mote emits bright light in a 20-foot radius, and dim light for another 20 feet. A non-undead creature that starts its turn in the bright light, or enters the bright light for the first time on a turn, must succeed on a Constitution saving throw or suffer a level of fatigue .

Additionally, if it suffers this fatigue, all undead in the area of bright light gain 2d8 temporary hit points and those in the area of dim light gain 1d8 temporary hit points. On a successful save, a creature is immune to the effect until it leaves the area.