Black Fog of Death, (眚 黑) ShengHei

Life Sense. The mist can sense the location of any creature within 60 feet of it, unless that creature’s type is construct or undead.

Misty Form. The mist can occupy another creature’s space and vice versa. In addition, if air can pass through a space, the mist can pass through it without squeezing. Each foot of movement in water costs it 2 extra feet, rather than 1 extra foot. The mist can’t manipulate objects in any way that requires fingers or manual dexterity.

Sunlight Hypersensitivity. The mist takes 10 radiant damage whenever it starts its turn in sunlight. While in sunlight, the mist has disadvantage on attack rolls and ability checks.

Aura of Misfortune. Creatures within 30 feet of the Black Fog of Death have disadvantage on saving throws and ability checks. Additionally, attack rolls against the Fog have disadvantage while within this aura.
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***Incorporeal Movement.*** The Blackfog can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.
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***Shadow Blend.*** While in dim light or darkness, the Blackfog can use a bonus action to become invisible until it moves, attacks, or is in bright light.

Multiattack.The Blackfog makes two Corrupting Touch attacks or uses Shadow Bolt twice.

Corrupting Touch. Melee Spell Attack: +7 to hit, reach 10 ft., one target. Hit: 18 (4d6 + 4) necrotic damage, and the target's hit point maximum is reduced by an amount equal to the necrotic damage taken. This reduction lasts until the target finishes a long rest. If the target's hit point maximum is reduced to 0, it dies.

Shadow Bolt. Ranged Spell Attack: +7 to hit, range 60 ft., one target. Hit: 21 (6d6) necrotic damage, and the target must succeed on a DC 15 Constitution saving throw or be blinded for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on a success.

Legendary Actions (3/round)
The Black Fog of Death can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time, and only at the end of another creature's turn. The Black Fog of Death regains spent legendary actions at the start of its turn.

Shadow Grasp. The Black Fog of Death targets one creature it can see within 30 feet. The target must succeed on a DC 15 Strength saving throw or be restrained by shadowy tendrils until the end of its next turn.

Whisper of Despair (Costs 2 Actions). The Black Fog of Death whispers words of despair to one creature it can see within 60 feet. The target must succeed on a DC 15 Wisdom saving throw or be incapacitated until the end of its next turn.

Consume Light (Costs 3 Actions). The Black Fog of Death extinguishes all nonmagical light within 60 feet and reduces the radius of magical light by half. Creatures in the area must succeed on a DC 15 Constitution saving throw or take 14 (4d6) necrotic damage.