Automaton Devastator (Heavy)

Brute. A melee weapon deals one extra die of its damage when the automaton hits with it (included in the attack).

Immutable Form. The automaton is immune to any spell or effect that would alter its form.

Multiattack. The automaton makes two shield bash attacks, any of which it can replace by making two heavy plasma blaster attacks.

Shield Bash. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 9 (2d4 + 4) bludgeoning damage. If the target is a Medium or smaller creature, it must succeed on a DC 15 Strength saving throw or be pushed 10 feet and be knocked prone.

Heavy Plasma Blaster. Ranged Weapon Attack: +5 to hit, range 100/400 ft., 1 target. Hit: 7 (1d10 + 2) fire damage.

Shield Master. While wielding a shield and not incapacitated, when the automaton succeeds on a Dexterity saving throw against an effect that allows it to take half damage, the automaton can use this reaction to take no damage instead. If the automaton fails it's Dexterity saving throw, it can use this reaction to take half damage instead of full damage.

Loyal Bodyguard. When another creature within 5 feet of the automaton is hit by an attack roll, the automaton causes itself to be hit instead.