BloodLord Taldarkus

Taldarkus is a demonic undead and this has both demon and vampire attributes.    He starts with one use of each legendary ability and when he drains blood he also gains uses of his Legendary abilities.  He does take double damage from Radiant and if burned by radiant must return to his home plane until summoned after a Long Rest. 

Note that drain minor creatures without intelligence or class levels can only restore him to his base one use of each ability. 

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

Bite. Melee Weapon Attack: +10 to hit, reach 5 ft., one willing creature, or a creature that is grappled by the vampire, incapacitated, or restrained. Hit: 17 (1d6 + 14) piercing damage plus 7 (2d6) necrotic damage. If the target is humanoid, it must succeed on a DC 15 Charisma saving throw or be charmed by the vampire for 1 minute. While charmed in this way, the target is infatuated with the vampire.

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 its hit point maximum is reduced to 0.

Rapier. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 12 (1d8 + 7) piercing damage.

Unarmed Strike. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) bludgeoning damage. The vampire can also grapple the target (escape DC 18) if it is a creature and the vampire has a hand free.

Parry. The vampire adds 3 to its AC against one melee attack that would hit it. To do so, the vampire must see the attacker and be wielding a melee weapon.

Legendary Actions:  Gains one Legendary action each time he bites someone.  Can only take one at the end of another creatures turn.  

Blood Defense: Tardarkus has one legendary save which lets him to succeed in a saving throw he just failed. 

Trance:   Target must make Wisdom save against DC 18 to resist this psychic attack.  If Taldarkus has drunk their blood they have disadvantage on the save. If they fail they are <condition>charmed</condition> until the end of their next turn or until they are attacked by the Demon Vampire.   If they succeed they take 2d6 (7 points) of psychic damage.  

Thrall. Consuming a creature’s blood which reduces them to zero hit points or moves them down the death spiral means that he can raise them as an undead minion.  They start with full hit points but are Vulnerable to Radiant damage and are treated as permanently charmed by Taldarkus.  If they die they can be raised normally.  If raised via an undead creation spell or ritual they now gain Taldarkus's legendary abilities but start without any initial uses each morning.