Calador

Spellcasting. 

Calador is a 6th-level spellcaster that uses Intelligence as his spellcasting ability (spell save DC 16; +7 to hit with spell attacks). Calador knows the following spells from the wizard’s spell list:

Cantrips (at will): Fire bolt, Light, shocking grasp

1st Level (4 slots): charm person, magic missile,Mage Armor, [spell]Shield[spell]

2nd Level (4 slots): hold person, misty step, Suggestion

3rd Level (3 Slots): Summon Undead, Spirit Shroud,Counterspell

4th Level (3 Slots): Confusion, Blight

Fey Ancestry. Calador has advantage on saving throws
against being Charmed, and magic can’t put him to sleep.

Ghoulish Vitality. When Calador is reduced to 0 hp he is
knocked unconscious but not killed. At the start of his next
turn he regains 24 (6d6) hp and wakes up. He loses this
ability if the Bone of Doresain is destroyed.

Bone Club: Melee Weapon Attack: 1d20+6 to hit, reach 5 ft., one target. Hit: 7 (1d6 + 4) bludgeoning damage.

Claw: Melee Weapon Attack: +5to hit, reach 5 ft., one target. Hit: 5 (1d4 + 3) slashing damage. 

Create Ghoul (once per day): Calador creates a ghoul from the body of a dead humanoid within 60 ft.The Ghoul is under Calador's command and will obey simple instructions, but the control is very weak and it will always tend to act on its violent nature. For details, see The Bone of Doresain.

Mind Rend (Recharge 5-6): A wave of madness flows out from the Bone. All creatures within 15 ft. must make a DC 16 Charisma save or take 7 (2d6) psychic damage.