Vampire, Elder Beguiler

Regeneration. The vampire regains 20 hit points at the start of its turn if it has at least 1 hit point and isn't in sunlight or running water. If the vampire takes radiant damage or damage from holy water, this trait doesn't function at the start of the vampire's next turn.

Spider Climb. The vampire can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Vampire Weaknesses. The vampire has the following flaws:

Forbiddance. The vampire can't enter a residence without an invitation from one of the occupants.

Harmed by Running Water. The vampire takes 20 acid damage when it ends its turn in running water.

Stake to the Heart. The vampire is destroyed if a piercing weapon made of wood is driven into its heart while it is incapacitated in its resting place.

Sunlight Hypersensitivity. The vampire takes 20 radiant damage when it starts its turn in sunlight. While in sunlight, it has disadvantage on attack rolls and ability checks.

Preternatural Deflection. While wearing no armor, the vampire's AC equals 13 + its Charisma modifier (already included).

Pervasive Influence. The vampire can target any creature with their Dominate action, not just beasts and humanoids.

Misty Escape. When it drops to 0 hit points outside of its resting place, the vampire transforms into a cloud of mist instead of falling unconscious, provided that it isn't in sunlight or running water. If it can't transform, it is destroyed.

While it has 0 hit points in its mist form, it can't transform back into its vampire form, and it must reach its resting place within 2 hours or be destroyed. Once in its resting place, it reverts back to its vampire form. It is then paralyzed until it regains 1 hit point. After spending 1 hour in its resting place with 0 hit points, it regains 1 hit point. 

Legendary Resistance (3/Day). When the vampire fails a saving throw, it can choose to succeed instead.

Multiattack. The vampire makes two attacks, only one of which can be a bite attack.

Claws. Melee Weapon Attack: +8 to hit, reach 5 ft., one creature. Hit: 8 (2d4 + 3) slashing damage. Instead of dealing damage, the vampire can grapple the target (escape DC 18).

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one willing creature, or a creature that is grappled by the vampire, incapacitated, or restrained. Hit: 6 (1d6 + 3) piercing damage plus 10 (3d6) necrotic damage. The target's hit point maximum is reduced by an amount equal to the necrotic damage taken, and the vampire regains hit points equal to that amount. The reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0.

Dominate (Recharge 4-6). The vampire targets one creature it can see within 30 feet of it. The target must succeed a DC 19 Wisdom saving throw or magically charmed by the vampire. The target makes this saving throw with advantage if it or its allies are fighting the vampire. While charmed this way, the target regards the vampire with trust and fascination, and is a willing target for its bite attack.

Each time the target takes damage, it can repeat the saving throw, ending the effect on itself on a success. The effect also ends if the vampire dies or takes a bonus action to end it. In any case, when the charm ends, the target is aware that the vampire influenced its mind.

Insidious Beckoning. The vampire targets one creature it can see within 60 feet of it. The target must make a DC 19 Wisdom saving throw. On a failure, the target takes 12 (4d6) psychic damage, and must choose between one of the following effects:

• The target moves 10 feet closer to the vampire. Until the end of the vampire's next turn, each 1 foot of distance the target moves away from the vampire costs an additional 1 foot of movement.
• The next saving throw the target makes before the end of the vampire's next turn is reduced by 1d4.

Terrify (1/Day). The vampire targets any number of creatures it can see within 30 feet of it. If a target can see the vampire, it must succeed a DC 19 Wisdom saving throw or be frightened for 1 minute. If a target fails their initial saving throw by 5 or more, it can only take the Dash, Dodge, or Hide actions while frightened this way. A frightened creature can repeat the saving throw at the end of its turn, ending the effect on itself on a success.

Voice of Agony and Ecstasy (1/Day Each). The vampire unleashes potent magic with its voice, choosing one of the options below:

• Captivating Song. The vampire targets any number of creatures it can see within 30 feet of it. If the target can hear the vampire, it must succeed a DC 19 Wisdom saving throw or be charmed by the vampire for 1 minute. While charmed this way, the target cannot take hostile actions against other creatures, and it cannot willingly move away from the vampire. The effect ends early if the target takes damage, or if another creature takes an action to shake the target to its senses.
• Shriek of Doom. The vampire unleashes a banshee-like shriek in a 30-foot cone. All creatures in this area must make a DC 19 Constitution saving throw, taking 36 (12d6) thunder damage on a failed save, or half damage on a successful one.

Swiftstep. The vampire moves up to half it's speed.

Take My Pain. When the vampire is targeted by an attack, spell, or other effect, and it is within 5 feet of creature it has charmed, the vampire can use its reaction to make the charmed creature the target instead of itself. 

The vampire 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 vampire regains spent legendary actions at the start of its turn.

Move. The vampire moves up to its speed without provoking opportunity attacks.

Claw. The vampire makes a Claw attack.

Bite (Costs 2 Actions). The vampire makes a Bite attack.

Beguile (Costs 3 Actions). The vampire immediately recharges and uses its Dominate action.