ghosts of the undead, any alignment
11th level armor
has 45 hit points (10d8)
You will fly at 40 feet per second (hover) at a speed of 0 feet.
- 7 (-2)
- 13 (+1)
- 10 (+0)
- 10 (+0)
- 12 (+1)
- 17 (+3)
Nonmagical attacks: Bludgeoning, Piercing, and Slashing; Acid, Fire, Lightning, Thunder
Poison, Necrotic, Cold immunity
Immunity Conditions: charred, exhausted, frightened, grappled, paralyzed, petrified, poisoned, prone, restraining
Passive Perception 11 ft., Darkvision 60 ft.
Languages Any language it knew in the past
1,100 XP Challenge 4
Gain 2 proficiency points
In Elemental Sight.
A ghost can see 60 feet into the Ethereal Plane when it is on the Material Plane, and the other way around.
Movement in the body. Other creatures and objects can be traversed by the ghost as if they were difficult terrain. If the creature ends its turn inside an object, it takes 5 (1d10) force damage.
Weeping Touch. Melee Weapon Attack: +5 to hit, range of 5 ft., one target. This attack deals 17 necrotic damage (4d6 + 3).ge.
From the Material Plane, the ghost enters the Ethereal Plane. While it can be seen on the Material Plane while in the Border Ethereal, and vice versa, it cannot affect or be affected by anything on the other plane.
A terrifying visage. Within 60 feet of a ghost, every non-undead creature that can see it must succeed on a DC 13 Wisdom saving throw or suffer 1 minute of fright. Saves that fail by 5 or more also age the target by 1d4 × 10 years. If a frightened target succeeds on its saving throw, it ends the frightened condition on itself. When a target’s saving throw succeeds, or when the effect ends for the target, the target is immune to this ghost’s Horrifying Visage for the next 24 hours. With a greater restoration spell, the aging effect can be reversed, but only within 24 hours.
Possession (Recharge 6).
If a humanoid is seen within 5 feet of the ghost, it must succeed on a DC 13 Charisma saving throw or be possessed by it; the ghost then vanishes, and the target is incapacitated and loses control of its body. Now, the ghost controls the target’s body but does not deprive him of consciousness. Ghosts cannot be targeted by any attack, spell, or other effect except those that turn them undead, and they retain their alignment, intelligence, wisdom, charisma, and immunity to being charmed and frightened. As a result, the possessed target’s statistics are used, but its knowledge, class features, and abilities are not accessed.
The possession ends when the body loses 0 hit points, when the ghost ends it as a bonus action, or when a dispel evil and good effect turns or forces it out. The ghost reappears within five feet of the body when the possession ends. Following a successful saving throw or after the possession ends, the target is immune to this ghost’s Possession for 24 hours.
Lair Actions are a great way to deal with this monster. You could also use legendaries.
While the ghost is on the Ethereal Plane, you could begin the encounter with an interesting “haunting” phase, where the party must determine how to draw the ghost into a confrontation on the Material Plane.
There is also the risk that that would also make an already difficult encounter even more difficult, so it is important to take this suggestion with a grain of salt.