Corrupted Behemoth Necromancer

Reclaim Anima (3/Day). If the Corrupted Behemoth fails a saving throw, it can drain the animating force from one undead creature it controls to succeed instead, reducing the creature to 0 hit points.

Multiattack. The Corrupted Behemoth makes two Necrotic Burst attacks.

Necrotic Burst. Melee or Ranged Spell Attack: +7 to hit, reach 5 ft. or range 120 ft., one target. Hit: 25 (4d10 + 3) necrotic damage.

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

At will: dancing lights, mage hand, prestidigitation

2/day each: bestow curse, dimension door, mage armor, web

1/day: circle of death

Summon Undead (2/Day). The Corrupted Behemoth magically summons five skeletons or zombies. The summoned creatures appear in unoccupied spaces within 60 feet of the Corrupted Behemoth, whom they obey. They take their turns immediately after the Corrupted Behemoth. Each lasts for 1 hour, until it or the Corrupted Behemoth dies, or until the Corrupted Behemoth dismisses it as a bonus action. If this feature is used again, all existing skeletons or zombies are destroyed as the new ones are created. 

Waste Away. When taking damage from an attack, the Corrupted Behemoth can become ethereal, taking half damage from that attack. 

Death Wish. When taking necrotic damage, the Corrupted Behemoth can redirect the energy, turning it into health for creatures under his control. The damage negated by the resistance is distributed among the minions equally as temporary HP. 

The Corrupted Behemoth has 3 Legendary Actions that renew on its turn. It may take legendary actions after another creature's turn.

Graveway Traveler. 1 Legendary Action. The Corrupted Behemoth can move up to 10 feet, step magically into an area of loose earth, and emerge from any area of loose earth within 60 feet, appearing in an unoccupied space within 5 feet of the second space.

Dread Mortality. 2 Legendary Actions. The Corrupted Behemoth stares into the soul of one creature within 60 feet in an attempt to frighten it. The target must make a DC 15 Wisdom saving throw or become frightened until the end of their next turn.

Blight. 3 Legendary Actions. The Corrupted Behemoth sends necrotic energy streaking through the ground in a 60 foot radius. All creatures within range must make a DC 15 Dexterity saving throw or take 11 (2d10) necrotic damage.