Magic Resistance.  The animated armor has advantage on saving throws against spells and other magical effects.

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

Animated Guardian.  The animated armor can be commanded by its creator as a bonus action on the creator's turn.  The armor follows the creator's commands to the best of its ability and acts during the same initiative count as the creator.

Anti-magic Susceptibility.  The animated armor is incapacitated while in the area of an antimagic field. If targeted by dispel magic, the armor must succeed on a Constitution saving throw against the caster's spell save DC or fall unconscious for 1 minute.

Reactive Armor. If the animated armor is subjected to lightning damage, it gains a bonus action on its next turn to make a great axe attack against a target within its reach.

Multi-attack. The animated armor makes two melee attacks

Great Axe. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 17 (2d12 + 5) slashing damage. 

Adamantine Shell. The animated armor can use its reaction to gain a +4 bonus to its AC against one attack that would hit it.  If the attack misses, the armor can make one great axe attack against the attacker as part of the same reaction.