Adaptive Alloy. If the mech drops below 100 hit points, it permanently gains 4 (1d6 + 1) bonus AC and reduces incoming magic damage by 11 (2d8 + 3) until it dies.

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

Lightning Absorption. Whenever the mech is subjected to lightning damage, it takes no damage and instead regains a number of hit points equal to the damage dealt.

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

Magic Weapons. The mech's weapon attacks are magical.

Punch. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 34 (5d8 + 13) bludgeoning damage.

Elbow Rocket (3/Long Rest). Melee Weapon Attack: +16 to hit, reach 5 ft., one target. Hit: 24 (3d10 + 10) bludgeoning damage. The target must make a DC 21 strength saving throw or be knocked back 20 ft. away, taking extra 12 (2d8 + 3) bludgeoning damage when hit a wall or hard object. When hit another creature, both takes damage and be knocked back with the main target. On a successful save, is not knocked back.

Focus Fire. Ranged Weapon Attack: +16 to hit, range 40/160 ft., one target. Hit: 30 (10d6) piercing damage.

Lil Turret (5/Long Rest). The mech drops a turret anywhere on the battlefield. The turret have 50 hit points and 20 AC. Size medium.

Turret Attack. The mech order all of its turret to attack a target within each turret's range. Ranged Weapon Attack: +16 to hit, range 30/120 ft., one target. Hit: 17 (4d8) piercing damage.

Real Steel. The mech can use its reaction to add 4 AC against an opportunity attack that would hit it.