Calamity Class Weapon: M1 Abrams

Adamantium Body. The M1 Abrams is immune to being critically hit.

Magic Resistance. The M1 Abrams has advantage on saving throws against spells and other magical effects.

Avoidance. If the M1 Abrams is subjected to an effect that allows it to make a saving throw to take only half damage, it instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.

Unusual Nature. The M1 Abrams doesn’t require air, drink, or sleep.

Siege Monster. The M1 Abrams deals double damage to objects and structures.

Radar. The M1 Abrams cannot be surprised.

Legendary Resistance (4/Day). If the M1 Abrams fails a saving throw, it can choose to succeed instead.

Multi-Attack. The M1 Abrams can make 4 Machine Gun attacks and 2 Main Cannon attacks.

Machine Gun. Ranged Weapon Attack: +19 to hit, range 60/120 ft., 1 target. Hit: 40 (3d10 + 19) piercing damage.

Main Cannon. Ranged Weapon Attack: +19 to hit, range 300/600 ft., 1 target. Hit: 63 (4d20 + 19) bludgeoning damage plus 128 (32d6) fire damage. When a creature is hit by this attack, it must succeed on a DC 27 Constitution saving throw or be stunned until the end of it's next turn.

Sensor. As a bonus action, the M1 Abrams can send out a blast of radar. This reveals the location of all creatures in a 600 ft radius to the M1 Abrams until the end of it's next turn.

Aiming System. As a bonus action, the M1 Abrams can give itself advantage on all attack rolls until the beginning of its next turn.

Shields Up. As a reaction, the M1 Abrams can create a magical shield around itself, giving it a +5 to AC until the beginning of it's next turn.

Retaliation. As a reaction, the M1 Abrams can make two Machine Gun attacks against a creature that has attacked it (whether or not they dealt damage).

The M1 Abrams can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. The M1 Abrams regains spent legendary actions at the start of its turn.

Move. The M1 Abrams moves up to its movement speed.

Machine Gun. The M1 Abrams makes two Machine Gun attacks.

Main Cannon (Costs 2 Actions). The M1 Abrams makes a Main Cannon attack.