Artor Morlin, Baron of Blood

Special Equipment. Artor Morlin wears +3 plate and a belt of fire giant strength, and he wields a +2 greatsword of life stealing called Shoonfangs.  

Shapechanger. If Artor isn’t in sunlight or running water, he can use his action to polymorph into a Tiny bat or a Medium cloud of mist, or back into his true form.

While in bat form, Artor can’t speak, his walking speed is 5 feet, and he has a flying speed of 30 feet. His statistics, other than his size and speed, are unchanged. Anything he is wearing transforms with him, but nothing he is carrying does. He reverts to his true form if he dies.

While in mist form, Artor can’t take any actions, speak, or manipulate objects. He is weightless, has a flying speed of 20 feet, can hover, and can enter a hostile creature’s space and stop there. In addition, if air can pass through a space, the mist can do so without squeezing, and it can’t pass through water. It has advantage on Strength, Dexterity, and Constitution saving throws, and it is immune to all nonmagical damage, except the damage it takes from sunlight.

Legendary Resistance (3/Day). If Artor fails a saving throw, he can choose to succeed instead.

Misty Escape. When he drops to 0 hit points outside his resting place, Artor transforms into a cloud of mist (as in the Shapechanger trait) instead of falling unconscious, provided that he isn’t in sunlight or running water. If he can’t transform, he is destroyed.

While he has 0 hit points in mist form, he can’t revert to his vampire form, and he must reach his resting place within 2 hours or be destroyed. Once in his resting place, he reverts to his vampire form. He is then paralyzed until he regains at least 1 hit point. After spending 1 hour in his resting place with 0 hit points, he regains 1 hit point.

Regeneration. Artor regains 20 hit points at the start of his turn if he has at least 1 hit point and isn’t in sunlight or running water. If he takes radiant damage or damage from holy water, this trait doesn’t function at the start of his next turn.

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

Vampire Weaknesses. Artor has the following flaws:

Forbiddance. Artor can’t enter a residence without an invitation from one of the occupants.

Harmed by Running Water. Artor takes 20 acid damage if he ends his turn in running water.

Stake to the Heart. If a piercing weapon made of wood is driven into Artor’s heart while he is incapacitated in his resting place, he is paralyzed until the stake is removed.

Sunlight Hypersensitivity. Artor takes 20 radiant damage when he starts his turn in sunlight. While in sunlight, he has disadvantage on attack rolls and ability checks. However, Artor can ignore this weakness for five rounds per day. 

Spellcasting. Artor is a 10th-level spellcaster. His spellcasting ability is Charisma (spell save DC 21, +13 to hit with spell attacks). He has the following paladin spells prepared:

1st level (4 slots): command, shield of faith, thunderous smite

2nd level (3 slots): branding smite, protection from poison

3rd level (2 slots): dispel magic, spirit shroud

Innate Spellcasting. Artor's innate spellcasting ability is Charisma (spell save DC 21). He can cast the following spells without using spell slots:

At-will: detect evil and good

3/day: enhance ability

1/day: dominate person

Multiattack. The blackguard makes three attacks with its glaive or its shortbow.

Shoonfangs. Melee Weapon Attack: +16 to hit, reach 5 ft., one target. Hit: 16 (2d6 + 9) slashing damage. Shoonfangs also deals 10 necrotic damage on a critical hit and then restores 10 hit points to Artor.

Bite. (Bat or Vampire Form Only). Melee Weapon Attack: +14 to hit, reach 5 ft., one willing creature, or a creature that is grappled by the vampire, incapacitated, or restrained. Hit: 10 (1d6 + 7) 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. A humanoid slain in this way and then buried in the ground rises the following night as a vampire spawn under the vampire’s control.

Charm. Artor targets one humanoid it can see within 30 feet of it. If the target can see him, the target must succeed on a DC 21 Wisdom saving throw against this magic or be charmed by him. The charmed target regards Artor as a trusted friend to be heeded and protected. Although the target isn’t under Morlin's control, it takes his requests or actions in the most favorable way it can, and it is a willing target for Artor’s bite attack.

Each time Artor or his companions do anything harmful to the target, it can repeat the saving throw, ending the effect on itself on a success. Otherwise, the effect lasts 24 hours or until Morlin is destroyed, is on a different plane of existence than the target, or takes a bonus action to end the effect.

Children of the Night (1/Day). Artor magically calls 2d4 swarms of bats or rats, provided that the sun isn’t up. While outdoors, Artor can call 3d6 wolves instead. The called creatures arrive in 1d4 rounds, acting as allies of Artor and obeying his spoken commands. The beasts remain for 1 hour, until Artor dies, or until he dismisses them as a bonus action.

Dreadful Aspect (Recharges after a Short or Long Rest). Artor exudes magical menace. Each enemy within 30 feet of the Baron of Blood must succeed on a DC 21 Wisdom saving throw or be frightened for 1 minute. If a frightened target ends its turn more than 30 feet away from Artor Morlin, the target can repeat the saving throw, ending the effect on itself on a success.

Smite. Immediately after Artor Morlin hits a target with an attack roll, he can force that target to make a DC 21 Constitution saving throw. On a failed save, the target suffers one of the following effects of the blackguard’s choice:

Blind. The target is blinded for 1 minute. The blinded target can repeat the save at the end of each of its turns, ending the effect on itself on a success.

Shove. The target is pushed up to 10 feet away and knocked prone.

Artor Morlin 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. He regains spent legendary actions at the start of his turn.

Move. Artor moves up to his speed without provoking opportunity attacks.

Melee Strike. Artor makes one melee attack.

Bite (Costs 2 Actions). Artor makes one bite attack.