Black Sun's Dawn

A column of black light crashes down upon a location you specify within range. Until the spell ends, a 30-foot-radius, 40-foot-high cylinder of dim light glimmers there.

When the cylinder appears, each creature in it must make a Constitution saving throw, taking 4d10 necrotic damage on a failed save, or half as much damage on a successful one. A creature must also make this saving throw whenever it ends its turn in the cylinder. A creature reduced to 0 HP by this damage dies instead of falling unconscious, and may not be returned to life by any spell.

If you’re within 60 feet of the cylinder, you can move it up to 60 feet as a bonus action on your turn.