Warlock of the Undead

Soul Hunger. When it reduces a creature to 0 hit points, the warlock can gain 15 temporary hit points.

Dreadful Might. The Warlock and its allies have advantage on attack rolls against any creature frightened by the warlock. 

Multiattack. The warlock makes three attacks with its Shortsword or two attacks with its Horrifying Bolt.

Shortsword. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) piercing damage damage plus 11 (3d6) necrotic damage. 

Horrifying Bolt. Ranged Weapon Attack: +7 to hit, range 120 ft., one target. Hit: 22 (4d10) necrotic damage and is pushed back 15 feet. Additionally the target must succeed on a DC 15 Wisdom saving throw or be frightened of the warlock until the end of the warlock's next turn.

Spellcasting. The warlock casts one of the following spells, using Charisma as the spellcasting ability (spell save DC 15):

At will: alter self, false life, mage armor (self only), mage hand, minor illusion, speak with dead

1/day each: circle of death, fear, greater invisibility

Necrotic Husk. In response to being reduced to 0 hit points the warlock can instead drop to 1 hit point and each creature within 30 feet to succeed on a DC 15 Constitution saving throw or become frightened and take 16 (3d10) necrotic damage, halved on a success.