Bang

Constructed Nature. Bang does not require air, food, drink, or sleep.

Rivet's Companion. Bang shares Rivet's initiative and takes its turn immediately after him. It can move and use reactions independently. Unless Rivet uses a bonus action to command it, Bang takes the Dodge action. If Rivet is incapacitated, Bang acts independently and prioritizes defending Rivet and carrying him to safety.

Six-Legged Stabilizers. Bang has advantage on ability checks and saving throws made to avoid being knocked prone or moved against its will. Bang can climb difficult surfaces without making an ability check.

Coordinated Crossfire. Once during each of Bang's turns, when it hits a creature that Rivet has damaged since the beginning of Rivet's previous turn, the attack deals an additional 3 (1d6) force damage.

Arcane Repairs. When the mending spell is cast on Bang, it regains 7 (2d6) hit points. Bang can benefit from this trait no more than once per minute.

Reinforced Energy Chamber. Bang has advantage on saving throws against effects that would deactivate, overload, or magically suppress its systems.

Loud Mechanisms. Bang's furnace, rotating barrel, grinding joints, and expressive whistles give it disadvantage on Dexterity (Stealth) checks.

Eldritch Bolt. Ranged Weapon Attack: +5 to hit, range 120/480 feet, one target. Hit: 12 (2d8 + 3) force damage. If the target is Large or smaller, Bang can push it up to 5 feet away.

Furnace Burst (Recharge 5-6). Bang vents burning purple energy in a 15-foot cone. Each creature in the area must make a DC 13 Dexterity saving throw, taking 13 (3d8) fire damage on a failed save or half as much on a successful one. Unattended flammable objects in the area ignite.

Adhesive Shell (2/Day). Bang fires a capsule of rapidly hardening arcane adhesive at one Large or smaller creature within 60 feet. The target must succeed on a DC 13 Dexterity saving throw or become restrained. A restrained creature can use its action to make a DC 13 Strength check, freeing itself on a success. The adhesive can also be destroyed; it has AC 12, 10 hit points, immunity to poison and psychic damage, and vulnerability to fire damage.

Skittering Reposition. Bang moves up to half its speed without provoking opportunity attacks. It usually uses this movement to create crossfire with Rivet, hide behind cover, or place its reinforced body between Rivet and an approaching enemy.

Aggressive Advance. Bang moves up to its speed toward a hostile creature it can see. It must end this movement closer to that creature than where it began.

Spiteful Retort (Recharge 6). When a creature Bang can see within 60 feet damages Rivet, Bang makes one Eldritch Bolt attack against that creature.

Emergency Brace. When Bang takes damage, it locks its six legs and rotates its reinforced plating toward the attack, reducing the damage by 7 (1d8 + 3). Bang cannot use this reaction while prone or restrained.