Alastair (Puppeteer)

Spellcasting. Alastair is a 20-level spellcaster. His spellcasting ability is Intelligence (spell save DC 14, +5 to hit with spell attacks). Alastair has following Wizard spells prepared:
Cantrips (at will): Chill touch, Mage Hand, Ray of Frost, Shocking Grasp, Toll The Dead
1st level (8 slots): Charm Person, False Life, Magic Missile, Ray of Sickness, Cause Fear
2nd level (6 slots): Blindnes/Deafness, Crown of Madness, Darkness, Levitate, Misty Step, Hold Person, Mind Spike
3rd level (4 slots): Animate Dead, Fear, Major Image, Slow, Feign Death, Vampric Touch, Enemies Abound, Life Transference 
4th level (4 slots): Confusion, Greater Invisibility, Hallucinatory Terrain, Phantasmal Killer  
5th level (2 slots): Scrying, Mislead, Dream, Geas

Cane Sword. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 12 (1d8 + 5) piercing damage. 
Strings. Melee Weapon Attack: +8 to hit, reach 20 ft., five targets. Hit: 12 (1d12 per string +5) slashing, necrotic damage.

The Show Must Go On. If a player were to go unconscious Alastair can bring them back at any HP.

Alastair is very powerful and can even manipulate his own form.

Puppeteer (Costs 1 Action). Alastair becomes ghost like, growing huge, and losing his lower half. In this form Alastair takes no damage, instead the damage is halved and distributed to all of his puppets.   
Puppets. Alastair can create dark reflections of recently deceased people and previous characters your players have swapped from.