Canoptek Reanimator

Reanimation Protocol. When the reanimators hit points are reduced to zero it makes a DC 15 constitution saving throw, on a success it reassembles itself and regains 32 (5d12) hit points. Each time the reanimator uses this feature after the first, the DC increases by 5. When it finish a short or long rest, the DC resets to 15.

Living Metal. The reanimator regains 9 hit points at the start of its turn. If the reanimator takes acid damage, this trait doesn't function at the start of the reanimator's next turn. The reanimator dies only if it starts its turn with 0 hit points and doesn't regenerate.

Fabricator Claw Array. Each allied construct regains 9 hit points if they start their turn within 5 feet of the reanimator. 

Matter Breakdown. If the reanimator starts its turn in the same space as a dead creature that is Large or smaller, the corpse is destroyed, leaving behind only equipment as the body is consumed and turned into raw energy.

Explodes. When the reanimator is reduced to 0 hit points and fails its reanimation protocol it has a chance to explode. Roll a d6, on a 6 the reanimator explodes, each creature within 15 feet must make a DC 15 Dexterity saving throw taking 27 (6d8) lightning damage on a failure or half as much on a success. 

Spellcasting. The reanimator casts one of the following spells, using Wisdom as the spellcasting ability (spell save DC 16):

At will: mending, spare the dying(Constructs only)

1/day each: see invisibility, 

Multiattack. The reanimator makes two claw attacks.

Fabricator's Claws. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 14 (2d10 + 3) slashing damage. 

Reanimation Beam. The reanimator fires a stream of nanoscarabs at a friendly Construct it can see within 60 feet of it. The Construct if dead is resurrected and regains 50 hit points and is cured of any blindness, deafness, and diseases affecting the target. For the next minute a Construct hit by this beam has advantage on saving throws made for reanimation protocol. 

Atomiser Beam. The reanimator fires a stream of nanoscarabs at a creature it can see within 60 feet. The creature must make a  DC 16 Dexterity saving throw, taking 54 (12d8) necrotic damage on a failure or half as much on a success.