Alpha 1

Legendary Resistance (3/Day). If the construct fails a saving throw, it can choose to succeed instead.

Death Burst. When the construct dies, it explodes in a burst of light. Each creature within 20 feet of it must make a DC 20 Dexterity saving throw, taking 70 (20d6) radiant damage on a failed save, or half as much damage on a successful one.

Gate Guardians. The construct prevents all forms of planar travel against targets it strikes as well as stopping spells such as gate, misty step, teleport, and any form of magical movement as stated. Additionally, conjuration magic that summons creatures such as conjure animals or planar ally will not work while within one mile of the construct.

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

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

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

Siege Monster. The deals Construct double damage to objects and structures.

Multiattack. The construct makes four attacks: two with its slam and two with its Astral Pillars.

Slam. Melee Weapon Attack: +19 to hit, reach 20 ft., one target. Hit: 62 (5d12 + 10) bludgeoning damage.

Twin Siegebreaker Cannon. Ranged Weapon Attack: +5 to hit, range 80/320. one target. Hit: 48 (9d8 + 12) Piercing damage.

Thundercoil Harpoon (Recharge 5-6). The dreadnought fires it's Thundercoil Harpoon at a creature within 120 ft, that creature must make a DC 20 Dexterity saving throw, taking 120 (24d10) bludgeoning damage and 30 (6d10) lightning damage on a failed save. If the target's size is huge or larger, they have disadvantage on the saving throw.

Cannon. Ranged Weapon Attack: +15 to hit, range 120 ft., one target. Hit: 10 (3d6) piercing damage plus 10 (3d6) Fire damage. Target must make a DC 18 Dexterity Save or be knocked back 10 ft.

Scan. The Battle Mech makes a perception check.

Shoulder Missiles (Cost 2 actions). Missiles pop up from the "shoulders" of the Battle Mech and fire 2d4 missiles that seek targets with a heat signature. Each missiles has a range of 240 ft, hits it's target automatically, and deals 1d6 fire damage and 1d6 piercing damage.