Clockwork Gear

Thaugmentized. When a creature is inside the Clockwork Gear, its voice is boomed to x 3 its normal levels for everyone outside listening.

Piloted. This Gear requires a pilot; With no pilot, it can take no actions. The Clockwork Gear, being non-sentient, inherits the pilots Intelligence, Wisdom, and Charisma. When incapacitated or destroyed, the pilot can eject to continue fighting.

Peak Performance. While above 100 Hit Points, the Clockwork Gear has multiattack, and can make two attacks of its choice per turn. Once it goes below 100 Hit Points, some of the internal mechanisms of the Clockwork Gear bend and snap under stress, removing multiattack and giving it only one attack per turn.

Protective Mode. The clockwork gear moves its metallic limbs and armaments closer to its body, raising its AC by +3 until its next movement, attack, or action. While in this mode, it automatically fails all Dexterity saves.

Slam. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit:  12 (2d10 + 2) bludgeoning damage. If the target takes more than 15 damage in this way, they are pushed back from the Clockwork Gear 10 ft.

Morning Star Flail. Melee Weapon Attack: +9 to hit, reach 40 ft., one target. Hit: 13 (2d10 + 2) piercing damage. If the target is over 10 ft away, it must succeed a DEX saving throw DC 12. On a failed save the chain whips, wrapping itself around the target and grappling them (broken by STR DC 20). While grappled, the target is restrained, has disadvantage on strength rolls and saving throws, and the chain cannot grapple another target. If the pilot chooses, they can use an action to reel in the chain 20ft per round, pulling the grappled target toward them. If the target makes it to the Clockwork Gear while still grappled, they suffer 28 (4d10 + 6) piercing and bludgeoning damage. If the chain breaks, this attack can no longer be used.

Loaded and Primed. The clockwork gear, using its internal mechanisms, loads and primes one of the three different types of cannon ammunition or loads another mobile ballista bolt. This action counts as an attack for the sake of multiattack. 

Firebomb Cannon. Ranged Weapon Attack:  reach 80 ft., 15 ft radius. A large bomb flies through the air, exploding into a large ball of flames. Each creature in that radius must make a DC 15 Dexterity saving throw, taking 15 (6d6) fire damage and, if a creature or a flammable object, igniting on a failed save, or half as much damage on a successful one. Until a creature takes an action to douse the fire, the target takes 5 (1d10) fire damage at the start of each of its turns.

Fragmentation Cannon. Ranged Weapon Attack:  reach 120ft., 10 ft radius. A bomb soars through the air, exploding upon contact, sending debris and shrapnel all around it. Each creature in that radius must make a DC 17 Dexterity saving throw, taking 16 (4d8) piercing damage on a failed save, or none on a successful one.

Gasbomb Cannon. Ranged Weapon Attack:  reach 80 ft., 25 ft radius. A large cloud of green, hazy mist explodes from the bomb.  Each creature in that radius must make a DC 13 Constitution saving throw, taking 13 (2d12) poison damage on a failed save, or half as much on a successful one. The gas persists for one round, then dissipates. Any creature that starts their turn inside the cloud must make a Constitution save of 13, taking 6 (1d12) damage on a failed save, or half as much on a successful one.

Mobile Ballista. Ranged Weapon Attack: +2  to hit, reach 200 ft., one target. A large, shoulder-mounted ballista fires an oversized bolt at the target. Hit:  20 (3d10 + 2) piercing damage.

Manganese Deterrent. On an approaching melee attack, a tiny hatch opens up from the top of the piloting chamber, igniting a blinding metal compound in a flash of light. Any attacker within a 5 feet of the Clockwork Gear must make a Constitution save of 14, and on a failed save has -5 to hit, blindness and deafness until their next turn, and suffers (2d4) thunder damage. This reaction can be used four times.

The clockwork gear can take 3 legendary actions, choosing from the options below. Each action can be taken at the end of another creature's turn. At the start of the clockwork gear's turn, it regains all its legendary actions.

Attack. (Costs 2 Actions) The Clockwork Gear can make one of its cannon attacks (whichever round is loaded and primed), one slam attack, or one morning star flail attack (assuming someone isn't grappled by the chain, in which case the Clockwork Gear can reel in a grappled target 20ft.).

Action. The Clockwork Gear can use a legendary action to switch bomb types in the main cannon which reloads and primes another round or reset the mounted ballista.

Manganese Mega Deterrent. When the clockwork gear has below 30 hp remaining, a large hatch pops up on the top of the piloting chamber. Every creature that is not unconscious or deafened within an 80 foot radius, including the clockwork gear's pilot, takes (2d8) thunder damage. Every creature outside of the chamber must make a Constitution save of 17, or suffer blindness and deafness until the end of their next turn. After this, the pilot can eject if he wishes.