Bhool Neta

Anti-Life Mastery. The Neta can cast the spell false life on a willing creature as if it were the caster.

Anti-life Nature. When the Neta kills a living creature, it gains temporary hit points equal to the creature's Constitution score. 

Kethrine Skin. The construct is made of kethrine. The Neta's soul cannot be removed from its body, and it has advantage on Con. saving throws while within 10ft. of another Bhoolian soldier. 

Immutable Form. The Neta's form cannot be altered by spells or other means.

Spellcasting. The Neta is a 9th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 15, +7 to hit with spell attacks). The Neta has following wizard spells prepared:
Cantrips (at will): message, mending, blade ward , anti-life ray

1st level (4 slots): false life, magic missile, shield, witch bolt, Tensor's floating disk, alarm, absorb elements, identify

2nd level (3 slots): blur, levitate, hold person, magic weapon

3rd level (3 slots): haste, protection from energy, slow, sending

4th level (3 slots): Otiluke's resilient sphere, banishment, locate creature, private sanctum

5th level (1 slot): Antilife shell, wall of force

Innate Spellcasting. The Neta can cast the spell false life and levitate at will, without expending material components. These spells can only be cast this way at their lowest level, and levitate can only target the caster.

Multiattack. The Neta can make two Staff of the Neta attacks.

Quarterstaff. Melee Weapon Attack: +7 to hit, reach 5ft, one target. Hit: 7(1d8+3) bludgeoning damage. 

Staff of the Neta. Ranged Weapon Attack: +7 to hit, range 60/180 ft., one target. Hit: 14 (2d10+3) force damage plus additional force damage equal to the number of temporary hit points the Bhool Neta has.

Anti-life Steal. If a creature within 120ft. of the Neta would gain temporary hit points, the Neta can use its reaction to prevent the creature from gaining those hit points, and the Neta gains a number of temporary hit points equal to the number of temporary hit points prevented.