Candle Jack

Legendary Resistance (2/Day). If Candle Jack fails a saving throw, he can choose to succeed instead.  

Namebound Curse.  If a creature says "Candle Jack" aloud within 120 feet of him or an object he's marked (e.g. a children's rhyme, a puppet, or candle), the creature must succeed on a DC 17 Charisma saving throw or become Namebound for 24 hours. 
While Namebound: 
   - Candle Jack knows your exact location.
   - He has advantage on attacks, saves, and spells targeting you.
   - Once per long rest, he may use Shadowstep to teleport directly next to a Namebound creature anywhere on the same plane

Living Shadow. 
In dim light or darkness:
   - Candle Jack has resistance to all damage except radiant.  
   - He may Hide as a bonus action. 
   - When he's hit by an attack, he may teleport 15 ft to an unoccupied shadow he can see as a reaction

Magic Resistance. Candle Jack has advantage on saving throws against spells and other magical effects

Multiattack. Candle Jack makes three attacks: two Binding Cords and one Shadowflame burst  

Binding cord.  Melee Weapon Attack: Attack:
+10 to hit, reach 10 ft., one target. 
Hit: 15 (2d8 + 6) slashing damage. 
Target must succeed on a DC 16 Strength saving throw or be Restrained. At the start of their turn, restrained targets take 9 (2d8) necrotic damage

Shadowflame Burst (Recharge 5-6).
Candle Jack erupts in flame-like shadow. Each creature within 10 ft must make a DC 17 Dexterity saving throw. On a failure, a creature takes 27 (6d8) necrotic damage and is blinded until the end of its next turn. On a success, it takes half damage and is not blinded.  

Name Reaper (1/day or Recharge 6). 
All Namebound creatures within 60 ft must make a DC 17 Constitution saving throw.
   - On a failed save, they take 45 (10d8) necrotic damage and are Paralyzed until the end of Candle Jack's next turn.
   - On a success, they take half damage and are not paralyzed. 

Snuff the Flame (At-Will). As a bonus action, Candle Jack extinguishes a nonmagical flame within 60 feet. A magical light can only be extinguished with a success on a DC 17 spellcasting ability check and only stays extinguished for 1 minute.  

Shadowstep. Teleport up to 60 feet to an unoccupied space in dim light or darkness. 

Fear the Sack.  
If Candle Jack reduces a creature to 0 HP, he may use his reaction to suck their body into his Extradimensional Sack. The victim is stable but unconscious, cannot be found by divination magic, and cannot leave unless:
   - Candle Jack is killed
   - A Wish, Plane Shift, or Dispel Evil and Good spell is used
   - The sack is physically opened (DC 18 Strength)
He can trap up to 2 creatures.

Candle Jack can take 3 legendary action per round, choosing from below:

Snuff Light. 
    Extinguish a light source within 60 ft.

Shadow Flit. 
   Teleport up to 30 ft to a shadow

Whiserbind (Costs 2).
   Force a creature that can hear him to make a DC15 Wisdom save or be Frightened for 1 minute.  Repeat the save at the end of each of its turns.