Belzak, Gulthias Vampire

Martial Advantage. Once per turn, Belzak can deal an extra 7 (2d6) damage to a creature he hits with a weapon attack if that creature is within 5 feet of an ally of Belzak that isn’t incapacitated.

Blood Amulet (3/day). Whenever Belzak deals damage to a creature, he can expend 1 charge to deal an extra 2d10 Necrotic damage to the target and force it to make a DC 15 Constitution saving throw. On a failed save, the target gains 1 Exhaustion level.

Legendary Resistance (3/Day, or 4/Day in Lair). If Belzak fails a saving throw, he can choose to succeed instead.

Dread Lord's Form. At the start of Belzak's turn, he regains 10 Hit Points if he is missing any, unless he took Radiant damage from sunlight on his last turn.

Spider Climb. Belzak can climb difficult surfaces, including along ceilings, without needing to make an ability check.

Gulthias Step. Whenever Belzak is bloodied, his movement speed is increased by 30 feet.

Vampire Weakness. Belzak has these weaknesses:

•   Forbiddance. Belzak can't enter a residence without an invitation from an occupant.
•   Stake to the Heart. If a weapon that deals Piercing damage is driven into Belzak's heart while he has the Incapacitated condition in his resting place, Belzak has the Paralyzed condition until the weapon is removed.
•   Sunlight. Belzak takes 15 Radiant damage if he starts his turn in sunlight. While in sunlight, Belzak has Disadvantage on attack rolls and ability checks.

Multiattack (Vampire Form). Belzak makes three attacks, once each with his Bloodthirster Scimitar and Crimson Scimitar, and once with either Blight or Festering Blast.

Multiattack (Unholy Form). Belzak makes three attacks, two with his grasping claws, and once with either Blight or Festering Blast.

Bloodthirster Scimitar (Vampire Form). Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 3 (1d6 + 7) slashing damage plus 12 (3d6) Necrotic damage.

Crimson Scimitar (Vampire Form). Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 3 (1d6 + 6) slashing damage plus 12 (3d6) Necrotic damage, and Belzak regains Hit Points equal to the Necrotic damage dealt by this attack.

Grasping Claws (Unholy Form). Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 2d8+4 Piercing damage, and Belzak can attempt to Grapple the target. If he succeeds, he can make one Bite attack against that target for free.

Bite. Constitution Saving Throw: DC 17, one creature within 5 feet that is willing or that has the Grappled, Incapacitated, or Restrained condition. Failure: 6 (1d4 + 4) Piercing damage plus 13 (3d8) Necrotic damage. The target's Hit Point maximum decreases by an amount equal to the Necrotic damage taken, and the vampire regains Hit Points equal to that amount. If a creature's hit point maximum is reduced to 0 by this damage, they die.

Spellcasting. Belzak can replace 2 of his attacks from Multiattack in order to cast one of the following spells, using Wisdom as the spellcasting ability (spell attack +10, spell save DC 18).

At Will: Detect Magic, Druidcraft, Pass Without Trace, Plant Growth.

3/day: Alustriel's Mooncloak, Antilife Shell (5th level), Dispel Magic (5th level), Insect Plague (5th level), Wall Of Stone.

2/day: Blood Tide (6th level), Transport Via Plants, Wall Of Thorns.

1/day: Reverse Gravity, Whirlwind.

Gulthias Step. Whenever Belzak is bloodied, he can Disengage as a Bonus Action.

Wavering Will. Belzak casts Command as a Bonus Action.

Fall Upon My Prey. Belzak can attempt to make a Grapple attack against one creature as a Bonus Action, and if he succeeds, he can immediately make one Bite attack against that creature for free.

Unholy Form: Once per day, Belzak can transform into a horrid bat-like monstrosity, with four distended limbs ending in grasping claws, which are equivalent to a +1 magic weapon. Large leathery wings sprout from his back, granting him a Fly speed of 60 feet. Any equipment Belzak is wearing or carrying is absorbed into this new form for its duration. He retains his spellcasting ability in this form, and his Bite attack deals an additional 3d8 Necrotic damage, and he regains Hit Points equal to this additional damage. This transformation lasts for one hour, unless Belzak decides to end it early.

Unholy Absorption: (In response to taking Acid, Cold, Fire, Lightning, Poison, Necrotic, Psychic, Radiant, or Thunder damage) Foul shadows capture some of the incoming energy, lessening its effect on Belzak and storing it for his next melee attack. Belzak has resistance to the triggering damage type until the start his next turn, and if Belzak already has resistance to the triggering damage type, he instead gains immunity to that damage type until the start of his next turn. Also, the first time Belzak hits with a melee attack on his next turn, the target takes an extra 3d6 damage of the triggering type, and this effect ends.

Belzak can take 3 legendary actions (or 4 when in his lair), choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature's turn. Belzak regains spent legendary actions at the start of his turn.

Beguile (3 Legendary Actions). Belzak casts Dominate Person, requiring no spell components and using Charisma as the spellcasting ability (spell save DC 17). Belzak can't take this action again until the start of his next turn. Belzak may maintain control over one dominated creature at a time with this ability without requiring concentration.

Agile Stalker (1 Legendary Action). Belzak moves up to half his speed, and makes one Crimson Scimitar attack, or one Grasping Claws attack.

Blight Whip (2 Legendary Actions). Belzak creates a vine-like whip covered in blighted thorns that lashes out toward a creature within 30 feet. Make a melee spell attack (+10 to hit) against the target. On a hit, the target takes 3d6 Piercing damage, and must make a Constitution saving throw (DC 18), gaining the Poisoned condition for one minute on a failure, and if it is Large or smaller, he can pull it up to 10 feet closer to him. The creature may make this save again at the start of each of its turns.

Transport to Gulthias' Domain. When Belzak is bloodied, he casts Transport Via Plants, touching the Gulthias Tree if it is still alive, and stepping into it. Belzak is then transported to Gulthias' demi-plane in the Shadowfell, where he must remain for at least 24 hours. Once that time has elapsed, if any Spawn of Gulthias are alive anywhere, Belzak can use this ability again and touch any tree in Gulthias' Domain in order to return to the plane where that creature exists, whereupon it transforms into a Young Gulthias Tree, and Belzak steps out of it. The Young Gulthias Tree reaches full maturity 1d4+3 weeks later.