Of course, light is not always a good thing in a fantasy world, and sometimes the mysterious glow in the distance is a signal fire for all the powers of evil to rally and stand forth, blending the shadow and the light and bending each one to their nefarious purpose.
Wondrous item, artifact (requires attunement)
This black iron lantern is 2 feet tall and a foot in diameter, with a skull-shaped hinged shutter inset with eyes of onyx and a handle of bone. When the shutter is opened, you can choose for the midnight beacon to radiate a lambent greenish glow in a 20-foot radius. All creatures except the one that opened the midnight beacon have disadvantage on saving throws against fear and against life drain and similar undead abilities that reduce a character's maximum hit points. Alternatively, you can command the midnight beacon to radiate darkness (as the spell) in a 30-foot cone-shaped area. A creature wielding the midnight beacon can see through any darkness the lantern creates.
Epic Attunement. If you are evil, you may use an action to call all undead within 300 feet toward you. Mindless undead automatically heed the summon while intelligent undead can attempt a Wisdom saving throw with a DC of 8 + your Charisma modifier + your proficiency bonus, to resist. Undead successfully called by the midnight beacon move at their maximum speed toward the beacon for a number of rounds equal to your level, as if compelled by a suggestion. Once the undead come within 30 feet of the midnight beacon, you can command the undead as if they were under the effects of a dominate person spell cast in an 8th-level spell slot. The undead get a saving throw with a DC of 8 + your Charisma modifier + your proficiency bonus. Undead called to the midnight beacon but not controlled typically attack any living creatures they encounter.
Sentience. The midnight beacon is a sentient neutral evil artifact with an Intelligence of 10, a Wisdom of 12, and a Charisma of 20. A midnight beacon possesses darkvision and ordinary senses with a range of 60 feet and can speak Common. On its own, the beacon can cast detect evil and good 3 times and hallow and animate dead once each. Once these spells are cast, you must complete a long rest for the midnight beaconto recharge the usages of these spells.
Personality. The beacon has the special purpose of defending and protecting the undead, and it can cast death ward three times on an evil creature as long as it is working to further that goal. Once the beacon does so, you must complete a long rest to reset the charges of this spell. A midnight beacon can dismiss any or all death ward effects it has created as an action. If you do not have the goal of defending and protecting the undead, it works against you and tries its best to steer you towards evil and necromancy.
Destroying the Beacon. The midnight beacon can be destroyed only when 1,001 sentient undead willingly destroy themselves and give up their unlife in the beacon’s presence.