Alkor, Spider Lord of disease

Legendary resistance (3/day). If Alkor fails a saving throw he can choose to succeed instead. 

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

Web Sense. While in contact with a web, the spider knows the exact location of any other creature in contact with the same web.

Web Walker. The spider ignores movement restrictions caused by webbing.

Innate Spellcasting. Alkor's spellcasting ability is Charisma (spell save DC 22). Alkor can innately cast the following spells, requiring no material components:

At will: Chill Touch, Sapping Sting, Dimension door.

3/day each: Raise dead, Animate Dead, Inflict Wounds, Ray of Enfeeblement, Vampiric touch.

1/day each: Finger of death, Circle of death, Create Undead, Blight, Albi-Dalzims horrid wilting, Storm of vengeance, Meteor swarm, Power word kill. 

Multiattack. Alkor makes two melee attacks.

Blade of Alkor. Melee Weapon Attack: +18 to hit, reach 5 ft., one target. Hit: 21 (4d6 + 7) slashing damage plus 22 (5d6) Necrotic damage. 

Web (Recharge 4–6). Ranged Weapon Attack: +10 to hit, range 30/60 ft., one creature. Hit: The target is restrained by webbing. As an action, the restrained target can make a DC 16 Strength check, bursting the webbing on a success. The webbing can also be attacked and destroyed (AC 12; hp 10; vulnerability to fire damage; immunity to bludgeoning, poison, and psychic damage).

Teleport. Alkor magically teleports, along with any equipment it was wearing or carried, up to 100 ft to an unoccupied space it can see.

Alkor can take 2 legendary actions, choosing from the options below. Only on legendary action can be used at a time and only at the end of another creatures turn. Alkor regains spent legendary actions at the start of his turn. 

Cast spell: Alkor innately casts any spell on his innate spell casting list. 

Corrupt touch (costs two points): Alkor touches another creature and the creature must make a DC 22 Charisma saving throw or be charmed by him for 1 hour. while charmed in this way, Alkor can command the creature to do anything he wishes.